CWE-348

CasaOS is an open-source Personal Cloud system. Due to a lack of IP address verification an unauthenticated attackers can execute arbitrary commands as `root` on CasaOS instances. The problem was addressed by improving the detection of client IP addresses in `391dd7f`. This patch is part of CasaOS 0.4.4. Users should upgrade to CasaOS 0.4.4. If they can't, they should temporarily restrict access to CasaOS to untrusted users, for instance by not exposing it publicly.

Termix is a web-based server management platform with SSH terminal, tunneling, and file editing capabilities. The official Docker image for Termix versions 1.5.0 and below, due to being configured with an Nginx reverse proxy, causes the backend to retrieve the proxy's IP instead of the client's IP when using the req.ip method. This results in isLocalhost always returning True. Consequently, the /ssh/db/host/internal endpoint can be accessed directly without login or authentication. This endpoint records the system's stored SSH host information, including addresses, usernames, and passwords, posing an extremely high security risk. Users who use the official Termix docker image, build their own image using the official dockerfile, or utilize reverse proxy functionality will be affected by this vulnerability. This issue is fixed in version 1.6.0.

Apache HTTP Server 2.4.53 and earlier may not send the X-Forwarded-* headers to the origin server based on client side Connection header hop-by-hop mechanism. This may be used to bypass IP based authentication on the origin server/application.

Traefik is a golang, Cloud Native Application Proxy. When a HTTP request is processed by Traefik, certain HTTP headers such as X-Forwarded-Host or X-Forwarded-Port are added by Traefik before the request is routed to the application. For a HTTP client, it should not be possible to remove or modify these headers. Since the application trusts the value of these headers, security implications might arise, if they can be modified. For HTTP/1.1, however, it was found that some of theses custom headers can indeed be removed and in certain cases manipulated. The attack relies on the HTTP/1.1 behavior, that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been addressed in release versions 2.11.9 and 3.1.3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS by default. In case of error it falls back to a non-TLS URL http://irclogs.nim-lang.org/packages.json. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.

Nimble is a package manager for the Nim programming language. In Nim release versions before versions 1.2.10 and 1.4.4, "nimble refresh" fetches a list of Nimble packages over HTTPS without full verification of the SSL/TLS certificate due to the default setting of httpClient. An attacker able to perform MitM can deliver a modified package list containing malicious software packages. If the packages are installed and used the attack escalates to untrusted code execution.

A vulnerability was found in mod_wsgi. The X-Client-IP header is not removed from a request from an untrusted proxy, allowing an attacker to pass the X-Client-IP header to the target WSGI application because the condition to remove it is missing.

The Web Application Firewall plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.1.2. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

Use of Less Trusted Source vulnerability in Apache APISIX. Attacker can take advantage of wolf-rbac plugin under default configuration to potentially pollute logs with spoofed identity information and exploit IP based access control rules. This issue affects Apache APISIX: from 1.2.0 through 3.16.0. Users are recommended to upgrade to version 3.17.0, which fixes the issue.

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. Prior to version 1.6.6, Fabio allows clients to remove X-Forwarded headers (except X-Forwarded-For) due to a vulnerability in how it processes hop-by-hop headers. Fabio adds HTTP headers like X-Forwarded-Host and X-Forwarded-Port when routing requests to backend applications. Since the receiving application should trust these headers, allowing HTTP clients to remove or modify them creates potential security vulnerabilities. Some of these custom headers can be removed and, in certain cases, manipulated. The attack relies on the behavior that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been patched in version 1.6.6.

A Use Of Less Trusted Source [CWE-348] vulnerability in Fortinet FortiPortal version 7.0.0 through 7.0.6 and version 7.2.0 through 7.2.1 allows an unauthenticated attack to bypass IP protection through crafted HTTP or HTTPS packets.

Client use of server error message in PostgreSQL allows a server not trusted under current SSL or GSS settings to furnish arbitrary non-NUL bytes to the libpq application. For example, a man-in-the-middle attacker could send a long error message that a human or screen-scraper user of psql mistakes for valid query results. This is probably not a concern for clients where the user interface unambiguously indicates the boundary between one error message and other text. Versions before PostgreSQL 17.1, 16.5, 15.9, 14.14, 13.17, and 12.21 are affected.

kcp is a Kubernetes-like control plane for form-factors and use-cases beyond Kubernetes and container workloads. Prior to 0.31.4 and 0.32.2, the kcp front-proxy does not remove inbound X-Remote-User, X-Remote-Group, or X-Remote-Extra-* identity headers before forwarding requests to shards. Any authenticated tenant can inject X-Remote-Group: system:masters, authorization.kcp.io/warrant, authentication.kcp.io/scopes, or a group used for per-workspace required-group gating, and the shard trusts these values as authenticated identity assertions. This allows cross-workspace impersonation, authorization bypass, and arbitrary reading, writing, or deletion of resources, secrets, RBAC data, APIExports, APIBindings, and LogicalClusters. This issue is fixed in versions 0.31.4 and 0.32.2.

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. In versions prior to 2.22.0, an attacker can bypass the allowed hosts validation by omitting the Host header and supplying an X-Forwarded-Host header set to a whitelisted domain. The AllowedHostsMiddleware trusts the X-Forwarded-Host header as a fallback when the Host header is absent. Since X-Forwarded-Host is a client-controllable header, this enables host header injection attacks such as password reset poisoning, cache poisoning, and server-side request routing manipulation. Any application using AllowedHostsConfig is affected when deployed without a reverse proxy that strips X-Forwarded-Host, or when accepting HTTP/1.0 connections. This issue has been fixed in version 2.22.0.

OpenRefine is a free, open source tool for working with messy data. Prior to version 3.8.3, the `export-rows` command can be used in such a way that it reflects part of the request verbatim, with a Content-Type header also taken from the request. An attacker could lead a user to a malicious page that submits a form POST that contains embedded JavaScript code. This code would then be included in the response, along with an attacker-controlled `Content-Type` header, and so potentially executed in the victim's browser as if it was part of OpenRefine. The attacker-provided code can do anything the user can do, including deleting projects, retrieving database passwords, or executing arbitrary Jython or Closure expressions, if those extensions are also present. The attacker must know a valid project ID of a project that contains at least one row. Version 3.8.3 fixes the issue.

Hermes WebUI before 0.51.307 contains an authentication bypass vulnerability that allows unauthenticated remote attackers to circumvent local-origin IP restrictions on onboarding endpoints by supplying a spoofed X-Forwarded-For header with a loopback address. Attackers can exploit this bypass to perform server-side request forgery against internal services including cloud metadata endpoints, overwrite LLM provider configuration and API keys with attacker-controlled values, or initiate OAuth device-code flows to obtain persistent access tokens stored in auth.json.

Unitronics Unistream Unilogic – Versions prior to 1.35.227 - CWE-348: Use of Less Trusted Source may allow RCE

vLLM is an inference and serving engine for large language models. In versions from 0.22.1 through 0.28.0, the operator-supplied model revision pin (--revision / --code-revision) is not propagated to several Hugging Face artifact loads for the FunAudioChat and Tarsier2 architectures: the WhisperFeatureExtractor and speech_tokenizer PreTrainedTokenizerFast loads in vllm/model_executor/models/funaudiochat.py and the Qwen2VLConfig.from_pretrained call used by Tarsier2ProcessingInfo in vllm/model_executor/models/qwen2_vl.py. As a result, deployments pinned to a reviewed revision still resolve these behavior-affecting processor, tokenizer, and config artifacts from the repository's default revision, so a later change to the upstream default branch can alter audio preprocessing, speech tokenizer behavior, or Tarsier2 configuration without any change to the operator's configured pin. This is a supply-chain integrity and reproducibility failure for pinned deployments; it is residual to the earlier fix tracked as GHSA-3ww4-5jv9-j5gm / CVE-2026-47155 and does not constitute remote code execution or a trust_remote_code=False bypass. The issue is fixed in version 0.28.0.

The Limit Login Attempts (Spam Protection) plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 5.3. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

@fastify/proxy-addr is a Fastify plugin that determines a request's client address behind trusted reverse proxies, and it backs Fastify request.ip and request.ips. In versions 3.0.0 through 5.1.0, a trust subnet written in IPv4-mapped IPv6 notation with an IPv4-sized prefix, such as ::ffff:10.0.0.0/8 instead of the correct ::ffff:10.0.0.0/104, is accepted without error but trusts every IPv4 address on the internet rather than the block it names. Because the socket peer then becomes trusted at hop 0, any unauthenticated client can supply an arbitrary X-Forwarded-For header and control the address the application reads, which defeats IP-based access control, rate limiting, geolocation, and audit logging. The plugin inherited this defect from the upstream proxy-addr module (CVE-2026-90711). The issue is fixed in @fastify/proxy-addr 5.1.1, and users should upgrade to 5.1.1 or later. As a workaround, ensure any IPv4-mapped IPv6 trust subnet uses a prefix length of at least 97, or express the range in plain IPv4 notation.

9Router is an AI router & token saver. Prior to 0.5.2, 9router determines whether a /v1 LLM proxy request is local by reading the client-controlled Host header, allowing a remote unauthenticated attacker to send Host: localhost and bypass API-key authentication. In the default configuration, this exposes the /v1 proxy to upstream provider calls using stored provider credentials and allows /v1/search with the searxng provider_options.baseUrl parameter to drive server-side requests to internal or cloud-metadata hosts. This issue is fixed in version 0.5.2.

Serilog before v2.1.0 was discovered to contain a Client IP Spoofing vulnerability, which allows attackers to falsify their IP addresses by specifying an arbitrary IP as a value of X-Forwarded-For or Client-Ip headers while performing HTTP requests.

The Hide My WP Ghost – Security Plugin plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 5.0.18. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address from logging in.

Glance through 0.8.5 contains an IP address spoofing vulnerability in the authentication handler that allows unauthenticated attackers to bypass brute-force lockout protections by supplying arbitrary values in the X-Forwarded-For request header when the server proxied option is enabled. Attackers can manipulate the leftmost value of the X-Forwarded-For header to make each login attempt appear to originate from a distinct IP address, preventing the per-IP failed-login counter from reaching the lockout threshold and enabling unlimited credential guessing against the authentication endpoint.

FileCodeBox before 2.4 contains a rate-limit bypass vulnerability in the IPRateLimit class that allows unauthenticated attackers to circumvent request throttling by supplying attacker-controlled X-Real-IP and X-Forwarded-For headers without verification of trusted reverse proxy origin. Attackers can supply unique spoofed IP values on each request to enumerate all possible share codes and retrieve other users' files without authentication.

The Brizy Page Builder plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.4.18. This is due to an implicit trust of user-supplied IP addresses in an 'X-Forwarded-For' HTTP header for the purpose of validating allowed IP addresses against a Maintenance Mode whitelist. Supplying a whitelisted IP address within the 'X-Forwarded-For' header allows maintenance mode to be bypassed and may result in the disclosure of potentially sensitive information or allow access to restricted functionality.

Eclipse Kura versions prior to 5.6.2 trust the client-supplied X-Forwarded-For HTTP header as the authoritative source of the client IP address in audit log entries. The org.eclipse.kura.web2 (Web Console) and org.eclipse.kura.rest.provider (REST API) components use this header as the primary IP source when initializing audit context, and org.eclipse.kura.jetty.customizer unconditionally installs Jetty's ForwardedRequestCustomizer on all HTTP/HTTPS connectors, causing HttpServletRequest.getRemoteAddr() to reflect the attacker-controlled header value. An unauthenticated remote attacker can exploit this vulnerability to bypass IP-based brute-force protections — such as fail2ban — by spoofing the logged IP address to a non-routable value, allowing a brute-force attack to proceed undetected, or to cause a denial of service against a third party by injecting a victim's IP address and triggering a ban on that address.

In OpenStack Zaqar before 22.0.2, WSGI transport mishandles the URL-Signature header. By sending a request with an empty URL-Signature header, an unauthenticated remote attacker who knows a target project's UUID may bypass both Keystone authentication and pre-signed URL verification, resulting in the ability to read, enumerate, create, and delete that project's queues, messages, claims, and subscriptions. By additionally claiming an administrative role, the attacker may also perform administrative operations, such as managing pools and flavors in admin_mode deployments. Only deployments using the WSGI transport with an authentication strategy configured are affected; the websocket transport is not affected.

Szafir SDK Web is a browser plug-in that can run SzafirHost application which download the necessary files when launched. In Szafir SDK Web it is possible to change the URL (HTTP Origin) of the application call location. An unauthenticated attacker can craft a website that is able to launch SzafirHost application with arbitrary arguments via Szafir SDK Web browser addon. No validation will be performed to check whether the address specified in `document_base_url` parameter is in any way related to the actual address of the calling web application. The URL address specified in `document_base_url` parameter is then shown in the application confirmation prompt. When a victim confirms the execution of the application, it will be called in the context of attacker's website URL and might download additional files and libraries from that website. When victim accepts the application execution for the URL showed in the confirmation prompt with the "remember" option before, the prompt won't be shown and the application will be called in the context of URL provided by the attacker without any interaction. This issue was fixed in version 0.0.17.4.

proxy-addr is a Node.js module that determines a request's client address behind trusted reverse proxies, and it backs Express req.ip and req.ips. In versions 1.1.0 through 2.0.7, a trust subnet written in IPv4-mapped IPv6 notation with an IPv4-sized prefix, such as ::ffff:10.0.0.0/8 instead of the correct ::ffff:10.0.0.0/104, is accepted without error but trusts every IPv4 address on the internet rather than the block it names. Because the socket peer then becomes trusted at hop 0, any unauthenticated client can supply an arbitrary X-Forwarded-For header and control the address the application reads, which defeats IP-based access control, rate limiting, geolocation, and audit logging. This is a fail-open regression introduced in version 1.1.0. The issue is fixed in proxy-addr 2.0.8, and users should upgrade to 2.0.8 or later. As a workaround, ensure any IPv4-mapped IPv6 trust subnet uses a prefix length of at least 97, or express the range in plain IPv4 notation.

OpenClaw before 2026.3.31 misclassifies proxied remote requests as loopback connections in the diffs viewer when allowRemoteViewer is disabled, allowing unauthorized access. Attackers can bypass access controls by sending proxied requests that are incorrectly identified as local loopback traffic, circumventing intended remote viewer restrictions.

Use of Less Trusted Source vulnerability in SolidWP Solid Security allows HTTP DoS.This issue affects Solid Security: from n/a through 9.3.1.

A security vulnerability has been detected in PbootCMS up to 3.2.12. The affected element is the function get_user_ip of the file core/function/handle.php of the component Header Handler. The manipulation of the argument X-Forwarded-For leads to use of less trusted source. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used.

The Unlimited Elements For Elementor (Free Widgets, Addons, Templates) plugin for WordPress is vulnerable to IP Address Spoofing in all versions up to, and including, 1.5.112 due to insufficient IP address validation and/or use of user-supplied HTTP headers as a primary method for IP retrieval. This makes it possible for unauthenticated attackers to bypass antispam functionality in the Form Builder widgets.

The WP Maintenance plugin for WordPress is vulnerable to IP Address Spoofing in all versions up to, and including, 6.1.9.2 due to insufficient IP address validation and use of user-supplied HTTP headers as a primary method for IP retrieval. This makes it possible for unauthenticated attackers to bypass maintenance mode.

HestiaCP versions 1.2.0 through 1.9.4 contain an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass authentication security controls by supplying an arbitrary IP address in the CF-Connecting-IP HTTP header without verifying the request originated from Cloudflare's network. Attackers can exploit this to circumvent fail2ban brute-force protection, bypass per-user IP allowlists, and poison authentication audit logs by spoofing trusted IP addresses on each request.

The IP Vault – WP Firewall plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 1.1. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

In Znuny through 7.3.6, an attacker can bypass specific standard login procedures and gain unauthorized access to sensitive system functions by manipulating a specific HTTP request header. Because the application incorrectly trusts this header, an attacker can impersonate any user, including administrators, without requiring a password. This grants full access to confidential data and system controls. More specifically, the HTTPBasicAuth modules for the agent (Kernel::System::Auth::HTTPBasicAuth) and customer (Kernel::System::CustomerAuth::HTTPBasicAuth) interfaces read the username to log in not only from $ENV{REMOTE_USER} (set by the web server after successful authentication), but also, as a fallback, from $ENV{HTTP_REMOTE_USER}, which is populated directly from an attacker-controllable "Remote-User" request header. On systems where HTTPBasicAuth was configured as the authentication backend, this allowed an attacker to log in as any existing user by sending a request with a forged Remote-User header, without providing any credentials.

Ghost CLI before 1.30.1 contains an IP spoofing vulnerability that allows unauthenticated remote attackers to bypass rate-limiting controls by manipulating the X-Forwarded-For header through a misconfigured Nginx configuration. Attackers can append attacker-controlled values to the header chain using the $proxy_add_x_forwarded_for directive to present an arbitrary IP address, circumventing Ghost's rate-limiting mechanisms on self-hosted instances.

LibreTranslate through 1.9.7, fixed in commit 397fd22, contains an IP spoofing vulnerability in the get_remote_address() function that allows unauthenticated attackers to spoof client IP addresses by injecting arbitrary values into the X-Forwarded-For header without trusted proxy validation. Attackers can bypass per-IP rate limiting and flood bans by supplying forged addresses in the X-Forwarded-For header to enable unlimited API abuse.

ProxySQL is a proxy for MySQL and its forks, as well as PostgreSQL. In versions 2.0.0 through 3.0.8, the ProxySQL MySQL frontend accepts the `PROXY UNKNOWN <addr> <addr> <port> <port>\r\n` PP1 frame as a well-formed PROXY protocol header. The HAProxy PROXY protocol v1 specification says that when the protocol token is `UNKNOWN`, the receiver MUST ignore any address fields that follow it, because the proxy has declared it cannot determine the client identity. ProxySQL parses those address fields anyway via `sscanf` and writes the spoofed source address into the session's `addr.addr` field. From there it flows directly into the query-rule matcher, where the `client_addr` predicate decides routing and ACL. When `mysql-proxy_protocol_networks = '*'` (the default), any TCP peer can send a PP1 frame and choose any source IP claim. With that, any `mysql_query_rules` row pinned to a `client_addr` value is forgeable: the attacker writes the address they want to match into the PP1 line, and ProxySQL routes their query as if it came from that address. In practice this is a routing and ACL bypass. Real deployments use `client_addr` for read-write splitting (internal apps go to the primary, public traffic to read replicas), per-app schema pinning, and query-filter rules (DDL allowed only from admin CIDR, public queries blocked from dangerous patterns). An attacker that can reach the frontend port can forge their way into any of those routes. Version 3.0.9 patches this issue.

The Caddy Defender plugin is a middleware for Caddy that allows users to block or manipulate requests based on the client's IP address. Prior to version 0.10.1, Caddy Defender used `r.RemoteAddr` when evaluating whether a request should be blocked. `RemoteAddr` is the address of the immediate peer connected to Caddy. In deployments where Caddy is behind a trusted proxy, CDN, or load balancer, the immediate peer is usually the proxy, not the original client. Caddy resolves the original client address into its `client_ip` request variable after applying the configured `trusted_proxies` policy, but Defender did not use that value. As a result, clients from blocked IP ranges could bypass Defender when accessing Caddy through a trusted proxy whose own IP address was not blocked. This affects deployments that use Defender behind trusted proxies and expect it to enforce blocking based on the real client IP. The issue is fixed in version 0.10.1 by making Defender prefer Caddys resolved `client_ip` request variable when it is available. Defender falls back to `RemoteAddr` only when Caddy has not provided a resolved client IP. There is no complete workaround in affected Defender versions for deployments that rely on Caddy's trusted proxy client IP resolution. Until upgrading, affected users should enforce equivalent IP blocking at the trusted proxy, CDN, load balancer, firewall, or other edge layer before traffic reaches Caddy. Deployments where Caddy receives traffic directly from clients, without an intermediate trusted proxy, are not affected by this bypass.

The AA Block Country plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 1.0.1. This is due to the plugin trusting user-supplied headers such as HTTP_X_FORWARDED_FOR to determine the client's IP address without proper validation or considering if the server is behind a trusted proxy. This makes it possible for unauthenticated attackers to bypass IP-based access restrictions by spoofing their IP address via the X-Forwarded-For header.

The Security, Antivirus, Firewall – S.A.F plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.3.5. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address from logging in.

Cleanuparr is a tool for automating the cleanup of unwanted or blocked files in Sonarr, Radarr, and supported download clients like qBittorrent. Prior to 2.9.10, TrustedNetworkAuthenticationHandler.ResolveClientIp parses the leftmost entry of the X-Forwarded-For header as the client IP. That entry is attacker-controlled — X-Forwarded-For is append-only, so the leftmost value is whatever the original HTTP client claimed. By sending a spoofed local IP in the header, an unauthenticated remote attacker passes the trusted-network check and is logged in as the Cleanuparr administrator. This vulnerability is fixed in 2.9.10.

The Limit Login Attempts Plus plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 1.1.0. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address or country from logging in.

Speedtest Tracker through 1.15.0 contains an IP allowlist bypass vulnerability that allows unauthenticated remote attackers to evade ALLOWED_IPS and Prometheus allowlists by spoofing X-Forwarded-For headers. Because bootstrap/app.php trusts every peer as a proxy, attackers can supply an allowlisted address to read /prometheus metrics and reach protected web and API endpoints.

Use of less trusted source vulnerability in PayTR Payment and Electronic Money Institution Inc. PayTR Virtual Pos iFrame API WHMCS Module allows Exploitation of Trusted Identifiers. This issue affects PayTR Virtual Pos iFrame API WHMCS Module: from v9.0.0 before v9.0.3.

The LOGIN AND REGISTRATION ATTEMPTS LIMIT plugin for WordPress is vulnerable to IP Address Spoofing in versions up to, and including, 2.1. This is due to insufficient restrictions on where the IP Address information is being retrieved for request logging and login restrictions. Attackers can supply the X-Forwarded-For header with with a different IP Address that will be logged and can be used to bypass settings that may have blocked out an IP address from logging in.

Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. From 1.6.6 until 1.7.2, the CVE-2025-48865 fix in proxy/http_headers.go uses protectHeaders for a hardcoded set of forwarded headers but omits the operator-configured ClientIPHeader, TLSHeader, and RequestID names. In proxy/http_proxy.go, HTTPProxy.ServeHTTP calls addHeaders to set these trust headers before Go ReverseProxy processes the inbound Connection header, allowing an unauthenticated client to name and remove the configured headers before the request reaches the backend. Deployments that enable the corresponding proxy.header options can therefore lose client-IP, TLS-termination, or request-correlation signals used by backend authorization and auditing; the options are empty by default, and the hardcoded protected forwarded headers are unaffected. This issue is fixed in version 1.7.2.

In `api-gateway` versions till `1.7.3`, The default rate-limit key resolver, `ClientIpKeyResolver`, derives the per-client bucket key from the leftmost element of the `X-Forwarded-For` request header. That element is supplied by the originating HTTP client and is not validated against any trusted-proxy list. A single attacker can therefore obtain an unlimited number of independent rate-limit buckets — one per unique header value — and completely bypass the gateway's request-rate limiting on every route that uses the shipped default configuration.

A security flaw has been discovered in Trusted Domain Project OpenDKIM up to 2.11.0. The impacted element is the function dkim_process_set of the file dkim.c of the component Tag Tokenizer. Performing a manipulation results in use of less trusted source. The attack may be initiated remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

OfflineIMAP before 8.0.3 trusts the server with their STARTTLS capability prior to authentication, which allows STRIPTLS/man-in-the-middle attacks, taking over the connection and extracting account credentials in cleartext.

Passbolt API before 5, if the server is misconfigured (with an incorrect installation process and disregarding of Health Check results), can send email messages with a domain name taken from an attacker-controlled HTTP Host header.

Pingvin Share X before 1.22.0 contains a rate limit bypass vulnerability that allows unauthenticated remote attackers to evade per-IP throttling because backend/src/main.ts unconditionally trusts proxy headers. Attackers can rotate spoofed X-Forwarded-For values against /api/auth/signIn, /api/auth/signIn/totp, and /api/auth/resetPassword to brute-force passwords and TOTP codes and forge logged client IP addresses.

simple-php-router through 5.4.1.7 contains an IP restriction bypass vulnerability in the IpRestrictAccess middleware that allows remote unauthenticated attackers to bypass IP whitelist and blacklist protections. Attackers can spoof X-Forwarded-For, CF-Connecting-IP, or Client-IP headers to impersonate whitelisted addresses or evade blacklists, gaining access to IP-restricted routes.

djust provides Phoenix LiveView-style reactive server-side rendering for Django with Rust-powered performance. Prior to version 1.0.7, the WebSocket `handle_mount` and `ViewRuntime._build_request` rebuild an `HttpRequest` via `RequestFactory().get(...)` with no `HTTP_HOST`, so `request.get_host()` defaulted to `"testserver"` on the live path. Host/subdomain/domain `TenantResolver`s then misresolved the tenant — `None` on the live path while the HTTP path resolved correctly. With `STRICT_MODE=False` the tenant-scoped managers returned unscoped rows (cross-tenant disclosure); with the default they returned an empty queryset (broken tenancy). This is fixed in djust 1.0.7. The handshake Host is extracted from the ASGI scope, validated against `ALLOWED_HOSTS` (the same logic as the CSWSH Origin gate, parsed with Django's `split_domain_port` so malformed Hosts are rejected at the boundary), and propagated — with the TLS scheme — into the reconstructed request, so live-path tenant resolution matches HTTP exactly. There is no known workaround on the live path short of upgrading. Users are most exposed when combined with `STRICT_MODE=False`.

Forgejo 13.0.0 through 16.0.4, when "[federation] ENABLED = true" is set, has a spoofing issue that affects identity integrity but does not allow account takeover or content modification. It does not verify that the HTTP Signature on an incoming ActivityPub activity was produced by the key belonging to the actor named in the activity body. The signature verification in routers/api/v1/activitypub/reqsignature.go validates the request signature, but the inbox activity handlers subsequently read the acting identity from the attacker-controlled JSON body without binding it to the verified signing key. Additionally, the signed Digest header is not recomputed against the received request body. A remote attacker who hosts a single valid ActivityPub actor and keypair can therefore submit signature-valid activities attributed to any actor identity they name.

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.3.3 before 4.12.27, the AWS API Gateway v1 adapter can drop a distinct repeated request header value because it de-duplicates values using a substring comparison instead of an exact match, so middleware or application logic that depends on the complete X-Forwarded-For chain, rate limiting, audit logging, or proxy-chain validation can receive incomplete data. This issue is fixed in version 4.12.27.

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on AWS Lambda@Edge, CloudFront delivers a request header that appears more than once as several separate entries. The adapter writes each value with Headers.set instead of Headers.append, so every value overwrites the previous one and only the last reaches the application. Repeated request headers such as X-Forwarded-For, Forwarded, and Via are silently truncated to a single value. Request middleware sees only the last value of a repeated header instead of the full chain. For applications that base access control on the X-Forwarded-For chain, this can weaken or alter that decision; for auditing, hop history is lost. This vulnerability is fixed in 4.12.25.

WWBN AVideo is an open source video platform. In versions up to and including 26.0, the `getRealIpAddr()` function in `objects/functions.php` trusts user-controlled HTTP headers to determine the client's IP address. An attacker can spoof their IP address by sending forged headers, bypassing any IP-based access controls or audit logging. Commit 1a1df6a9377e5cc67d1d0ac8ef571f7abbffbc6c contains a patch.

Movable Type contains an issue with use of less trusted source. If exploited, tampered email to reset a password may be sent by a remote unauthenticated attacker.

Bypass Connection Restriction vulnerability in Hitachi Infrastructure Analytics Advisor (Data Center Analytics component), Hitachi Ops Center Analyzer  (Hitachi Ops Center Analyzer detail view component).This issue affects Hitachi Infrastructure Analytics Advisor:; Hitachi Ops Center Analyzer: from 10.0.0-00 before 11.0.4-00.

An issue was discovered in the oidc (aka OpenID Connect Authentication) extension before 4.0.0 for TYPO3. The account linking logic allows a pre-hijacking attack, leading to Account Takeover. The attack can only be exploited if the following requirements are met: (1) an attacker can anticipate the e-mail address of the user, (2) an attacker can register a public frontend user account using that e-mail address before the user's first OIDC login, and (3) the IDP returns an email field containing the e-mail address of the user,

Use of a less trusted source in the DKIM signing of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write signed with the DKIM key of a domain the server hosts, so that it passes DKIM and DMARC for that domain at other receivers. With DKIM signing enabled for a hosted domain, the server signed every message on its first delivery pass as the domain named in its From header, before local delivery, whatever the message's origin and without checking that its sender had authenticated. A sender anywhere could therefore send the server, as ordinary inbound mail, a message whose From is any address at such a domain, and the server signed it with that domain's key. Every copy the server then sent on to an address outside carried a valid signature aligned with the forged From, whatever the domain's DMARC policy: an account's forward, a mail rule's forward or copy, a Sieve redirect, an alias or distribution list with an outside member, the mirror copy, a managed-list or journal copy, or a message released from quarantine. A signed copy can also be re-sent to other recipients while the domain's key is unchanged. Exploitation needs DKIM signing to be enabled for the hosted domain (it is off until configured) and, for the forgery to leave the server, a forward, alias, list or rule that carries the domain's mail to an outside address. The signer likewise signed a message submitted over authenticated SMTP as whatever hosted domain its From header named, a header authenticated SMTP does not hold to the submitting account, so that an account of one hosted domain could have mail written in the name of another hosted domain signed with that domain's key; this mattered where the server holds signed-in senders to their own envelope addresses (SmtpAuthenticatedSenderCheck, off by default), as the signature was then the remaining way for such mail to pass the other domain's DMARC policy.

Gophish through 0.12.1 contains a rate limit bypass vulnerability that allows unauthenticated attackers to evade /login throttling by spoofing X-Forwarded-For or X-Real-IP headers. Attackers can send a different forwarded address per request so the limiter keyed on rewritten RemoteAddr never triggers, enabling unlimited password guessing and credential stuffing.

PyJWT is a Python implementation of JSON Web Token standards. From 2.1.0 until 2.15.0, PyJWT OKPAlgorithm.from_jwk in jwt/algorithms.py is affected because private-JWK import path does not compare the public key derived from d with x. This occurs when an OKP private JWK supplies non-corresponding x and d components. As a result, identity derived from x can differ from operations performed with d. Consequently, if an integration also accepts private key parameters from a proof header without rejecting them, an attacker may use a stolen sender-constrained token without the legitimate private key. This issue is fixed in version 2.15.0.

The Forminator Forms WordPress plugin before 1.57.2.1 does not verify that a request came from a trusted proxy before preferring client-supplied forwarding headers over the connecting address, and it uses that value both to enforce its per-visitor voting limit and to record who submitted an entry. Unauthenticated visitors can therefore vote without limit on any poll and can choose the address stored against every submission they make.

CodeIgniter is a PHP full-stack web framework. In versions prior to 4.7.4, IncomingRequest::isSecure() trusted the X-Forwarded-Proto and Front-End-Https headers from any incoming request, allowing an attacker could spoof these headers and cause the application to incorrectly treat an HTTP request as secure. This may have impacted applications that rely on isSecure(), force_https(), forceGlobalSecureRequests, or similar logic to enforce HTTPS-only access or make security-sensitive decisions. Exploitability depends on deployment configuration. Applications are most exposed if the backend is reachable directly over HTTP, or if a reverse proxy/load balancer forwards client-supplied forwarding headers without stripping or overwriting them. This issue has been fixed in version 4.7.4.

The optional feature 'Anti-Virus & Sandbox' of i-FILTER contains an issue with improper pattern file validation. If exploited, the product may treat an unauthorized pattern file as an authorized. If the product uses a specially crafted pattern file, information in the server where the product is running may be retrieved, and/or cause a denial of service (DoS) condition.

Use of a less trusted source for the envelope sender in the external-account download of Progressive Robot hMailServer 6.0.0 through 6.3.6 allows a remote unauthenticated attacker to have mail they write in the name of a domain the server hosts sent on by the server with an envelope sender at that domain, so that it passes the domain's SPF and DMARC at other receivers. A message the server downloads from an external POP3 or IMAP account has no SMTP envelope of its own, and the server took the address in its From header as its envelope sender, whatever that address was. A forward or redirect of the downloaded message to an outside address then left with that address as its envelope sender, which the Sender Rewriting Scheme leaves alone for a hosted domain, so that the receiver's SPF check passed for the forged domain, aligned even under strict alignment, with no non-default setting, host name record or DMARC policy needed. An attacker needs to know a mailbox elsewhere that an account here collects and forwards to an outside address; an account holder who adds an external account of their own can collect from a server of their own, which matters where SmtpAuthenticatedSenderCheck holds signed-in senders to their own addresses.

Wheels 4.0.6 through 4.1.2 lets an unauthenticated client switch a request into a separate test application context, including in production, by supplying an X-Wheels-Test-Context header or WHEELS_TEST_CONTEXT cookie with any value, or including a test-runner path anywhere in the URL, even the query string. The alternate application uses the same configuration, environment, datasource and debug settings: this is not an authentication bypass or data/debug escalation. It can bypass maintenance mode enabled only at runtime, provide a second set of in-memory rate-limit counters, and trigger additional application-startup side effects and memory use. This is fixed in 4.2.0.

The wpForo Forum WordPress plugin from 3.0.0 before 3.1.6 does not verify the source of client-supplied IP address headers before using them to key its per-visitor rate limit on paid AI requests, allowing unauthenticated attackers to bypass the limit by spoofing the header and exhaust the site owner's metered AI credits.

fastify is a fast and low overhead web framework for Node.js. Impact: the fix for CVE-2026-3635 added a guard on the forwarded-header reads used to derive the request host, protocol, hostname, ip, and ips values, checking the connecting address. That guard closes the IP, CIDR, and custom-function forms of trustProxy correctly, because those forms compile to predicates that inspect the connecting address. The hop-count form, where trustProxy is set to a number, compiles to a predicate that structurally ignores the address, so the guard is always satisfied for any hop count of one or more. Applications configured with a numeric trustProxy value, such as trustProxy set to 1 for a single reverse proxy, remain vulnerable: an attacker who can reach the Fastify origin directly, bypassing the front-facing proxy, can spoof the forwarded request fields exactly as in the unpatched version. The impact class matches the parent CVE-2026-3635, including host injection in generated URLs, HTTPS-enforcement bypass, secure-cookie and CSRF-origin bypass, and host-based routing and cache poisoning. Affected versions are fastify from 5.8.3 up to but not including 5.12.1. Patches: patched in fastify 5.12.1, where the numeric form of trustProxy is disabled at runtime and removed from the TypeScript type union. Workarounds: migrate to an IP, CIDR, or custom-function trustProxy value that validates the connecting address, and ensure the Fastify origin is only reachable through the trusted proxy chain.

In sshd in OpenSSH before 10.4, DisableForwarding=yes was supposed to take precedence over PermitTunnel=yes, but did not.

Summary When trustProxy is configured with a restrictive trust function (e.g., a specific IP like trustProxy: '10.0.0.1', a subnet, a hop count, or a custom function), the request.protocol and request.host getters read X-Forwarded-Proto and X-Forwarded-Host headers from any connection — including connections from untrusted IPs. This allows an attacker connecting directly to Fastify (bypassing the proxy) to spoof both the protocol and host seen by the application. Affected Versions fastify <= 5.8.2 Impact Applications using request.protocol or request.host for security decisions (HTTPS enforcement, secure cookie flags, CSRF origin checks, URL construction, host-based routing) are affected when trustProxy is configured with a restrictive trust function. When trustProxy: true (trust everything), both host and protocol trust all forwarded headers — this is expected behavior. The vulnerability only manifests with restrictive trust configurations.