CWE-625
Permissive Regular Expression
Extended description
This effectively causes the regexp to accept substrings that match the pattern, which produces a partial comparison to the target. In some cases, this can lead to other weaknesses. Common errors include: not identifying the beginning and end of the target string using wildcards instead of acceptable character ranges others
Common consequences1
- Access ControlBypass Protection Mechanism
Potential mitigations1
- Implementation
When applicable, ensure that the regular expression marks beginning and ending string patterns, such as "/^string$/" for Perl.
CVEs referencing this CWE23
| CVE | Description | Severity | EPSS | Flags | Modified |
|---|---|---|---|---|---|
| CVE-2018-8926 | Permissive regular expression vulnerability in synophoto_dsm_user in Synology Photo Station before 6.8.5-3471 and before 6.3-2975 allows remote authenticated users to conduct privilege escalation attacks via the fullname parameter. | NONE | 1.71%p77 | 2026-06-17 | |
| CVE-2023-6544 | A flaw was found in the Keycloak package. This issue occurs due to a permissive regular expression hardcoded for filtering which allows hosts to register a dynamic client. A malicious user with enough information about the environment could jeopardize an environment with this specific Dynamic Client Registration and TrustedDomain configuration previously unauthorized. | MEDIUM5.4 | 1.08%p65 | 2026-06-17 | |
| CVE-2026-23651 | Permissive regular expression in Azure Compute Gallery allows an authorized attacker to elevate privileges locally. | MEDIUM6.7 | 0.62%p49 | 2026-06-19 | |
| CVE-2026-83618 | xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.10 until 0.9.12, the requireWellFormed: true serializer validates DocumentType.publicId and DocumentType.systemId with PubidLiteral_match and SystemLiteral_match expressions produced by reg() in lib/grammar.js, which inherit the multiline flag. A complete valid literal on the first line can therefore satisfy the matcher while U+000A, U+000D, U+2028, or U+2029 and breakout markup remain in the emitted <!DOCTYPE ...> declaration. This bypasses the strict-serialization mitigation for the earlier DocumentType injection advisory; creation and direct property assignment remain unvalidated by design. This issue is fixed in @xmldom/xmldom version 0.9.12. | NONE | 0.57%p47 | 2026-09-08 | |
| CVE-2026-83617 | xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.11 until 0.9.12, the requireWellFormed: true element and attribute name checks use the anchored QName_exact expression produced by reg() in lib/grammar.js, which inherits the multiline flag. A name with a valid first line followed by U+000A, U+000D, U+2028, or U+2029 and breakout markup therefore passes validation and is emitted verbatim in element start and end tags or attribute names. This bypasses the strict-serialization checks introduced for the earlier element-name and attribute-name injection advisories, while the default serialization path remains outside the strict guarantee. This issue is fixed in @xmldom/xmldom version 0.9.12. | NONE | 0.57%p47 | 2026-09-08 | |
| CVE-2026-83609 | xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0 until 0.9.12, the shared reg() builder in lib/grammar.js compiles the anchored QName_exact validator with the multiline flag, so ^ and $ validate only one line instead of the complete name. createElementNS, createAttributeNS, createDocumentType, and createAttribute consequently accept a malformed XML name whose first line is valid and whose later text injects markup when serialized through either the default path or requireWellFormed: true. The triggering ECMAScript line terminators are U+000A, U+000D, U+2028, and U+2029. This issue is fixed in @xmldom/xmldom version 0.9.12. | NONE | 0.54%p45 | 2026-09-08 | |
| CVE-2020-8910 | A URL parsing issue in goog.uri of the Google Closure Library versions up to and including v20200224 allows an attacker to send malicious URLs to be parsed by the library and return the wrong authority. Mitigation: update your library to version v20200315. | MEDIUM6.5 | 0.54%p45 | 2026-06-17 | |
| CVE-2026-82726 | Permissive Regular Expression vulnerability in ash-project ash_phoenix lets a remote client select the tenant an Ash application uses, or degrade the request, by sending a crafted Host header. AshPhoenix.Helpers.get_subdomain/2 stripped the root domain with String.replace(host, ~r/.?#{root_host}/, ""). The root host was interpolated raw, so each . became a wildcard and any metacharacter a pattern, and the replace was global and unanchored, so a match was removed from anywhere in the string. With root_host example.com, Host: foo.exampleXcom.attacker.net returned the tenant foo.attacker.net. A metacharacter-bearing or nil root host degraded the pattern or raised on every request. The comparison was also case-sensitive, so TENANT.EXAMPLE.COM and EXAMPLE.COM slipped past the root-host allowlist. conn.host comes from the client Host header. The fix matches the root host case-insensitively and only as an exact trailing suffix. This issue affects ash_phoenix: from 2.1.26 before 2.3.25. | NONE | 0.52%p44 | 2026-09-01 | |
| CVE-2026-55536 | PraisonAI is a multi-agent teams system. Prior to praisonai 4.6.58, Browser Server _handle_connection() checks Chrome extension origins with re.match() and the unanchored expression chrome-extension://[a-z0-9]{32}. Extra trailing characters pass before websocket.accept(), allowing start_session commands and unauthorized browser automation. This issue is fixed in version 4.6.58. | CRITICAL9.1 | 0.52%p44 | 2026-09-09 | |
| CVE-2026-32973 | OpenClaw before 2026.3.11 contains an exec allowlist bypass vulnerability where matchesExecAllowlistPattern improperly normalizes patterns with lowercasing and glob matching that overmatches on POSIX paths. Attackers can exploit the ? wildcard matching across path segments to execute commands or paths not intended by operators. | CRITICAL9.8 | 0.41%p35 | 2026-06-17 | |
| CVE-2026-64940 | Tegalog -Fumy Otegaru Memo Logger- provided by Nishishi Factory contains a vulnerability due to a permissive regular expression, which may allow an attacker who can access the affected product to log in to the management console. As a result, the attacker may perform any operations available from the management console. | HIGH8.6 | 0.40%p34 | 2026-10-24 | |
| CVE-2026-14814 | GitLab has remediated an issue in GitLab CE/EE affecting all versions before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2 that, under certain conditions, could have allowed a user to poison cached responses for raw repository files, causing targeted users' CI/CD pipelines to execute specially crafted content and potentially exposing protected environment variables, due to improper validation of repository references. | HIGH8.2 | 0.39%p33 | 2026-10-14 | |
| CVE-2026-73845 | CKAN MCP Server is a tool for querying CKAN open data portals. Prior to 0.4.112, the ckan_get_mqa_quality and ckan_get_mqa_quality_details tools in src/tools/quality.ts use isValidMqaServer to validate the server_url parameter with a prefix-only regular expression for dati.gov.it, allowing suffix-host and URL-userinfo values to target an attacker-controlled host and return a spoofed response. This issue is fixed in version 0.4.112. | MEDIUM5.3 | 0.38%p32 | 2026-09-18 | |
| CVE-2026-79965 | Dell SCG 5.0 Appliance versions prior to 5.36.00.16 and Dell SCG 5.0 Application versions prior to 5.36.00.00, contains an External Control of Critical State Data vulnerability. An unauthenticated attacker with remote access could potentially exploit this vulnerability, leading to unauthorized access. | MEDIUM5.3 | 0.35%p28 | 2026-09-09 | |
| CVE-2026-19278 | A flaw was found in StackRox/RHACS Central's Auth Machine-to-Machine (M2M) token exchange. When an administrator configures M2M role mappings, the system uses unanchored regular expressions for matching claim values. This allows an attacker with a valid OpenID Connect (OIDC) token, whose claim value is a superstring of a configured pattern, to gain unauthorized access to roles they were not intended to receive. This can lead to privilege escalation within the system. | MEDIUM6.8 | 0.35%p28 | 2026-10-23 | |
| CVE-2026-102983 | Astro is a web framework for content-driven websites. From 5.2.0 until 8.2.4, the @astrojs/netlify adapter generates regular expressions for Netlify Image CDN remote-image allowlists without anchoring them to the beginning of the URL. Because Netlify evaluates these expressions with RegExp.test(), an allowed origin appearing only in a source URL's path or query can satisfy image.domains or image.remotePatterns while the URL's actual host remains attacker-controlled. An unauthenticated request to the public /.netlify/images endpoint can therefore cause the Image CDN to request attacker-selected URLs and may probe or reach internal services. Netlify egress protections may constrain reachable targets, and image transformation limits direct response exfiltration; no confidentiality or integrity impact has been demonstrated. This issue is fixed in version 8.2.4. | NONE | 0.31%p24 | 2026-09-30 | |
| CVE-2026-40110 | Jupyter Server is the backend for Jupyter web applications. In versions 2.17.0 and earlier, the Origin header validation uses Python's re.match() to check incoming origins against the allow_origin_pat configuration value. Because re.match() only anchors at the start of the string and does not require a full match, a pattern intended to match only a trusted domain (e.g., trusted.example.com) will also match any origin that begins with that domain followed by additional characters (e.g., trusted.example.com.evil.com). An attacker who controls such a domain can bypass the CORS origin restriction and make cross-origin requests to the Jupyter Server API from an untrusted site. This issue has been fixed in version 2.18.0. | HIGH7.3 | 0.31%p24 | 2026-07-31 | |
| CVE-2026-102830 | JupyterLab is an extensible environment for interactive and reproducible computing, based on the Jupyter Notebook Architecture. From JupyterLab 3.0.0 until 4.5.11 and 4.6.4, and in JupyterLite Core 0.8.3 and earlier, the Plural-Forms header in a selected third-party language pack can append JavaScript after a valid plural rule because prefix-only regular-expression validation accepts a matching prefix without requiring the entire header to match. JupyterLab passes the accepted expression to new Function, so loading the catalogue and translating a plural string executes the appended code in the authenticated JupyterLab origin. Where Jupyter Server kernels, terminals, and APIs are exposed, the code can use authenticated server APIs to read or modify files and run code. Impact is much more limited in JupyterLite because it typically lacks most exposed Jupyter Server surfaces. The default English locale is unaffected because it does not load a translation catalogue. This issue is fixed in JupyterLab 4.5.11 and 4.6.4 and JupyterLite Core 0.8.4. | MEDIUM6.8 | 0.26%p18 | 2026-10-01 | |
| CVE-2026-34763 | Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Directory interpolates the configured root path directly into a regular expression when deriving the displayed directory path. If root contains regex metacharacters such as +, *, or ., the prefix stripping can fail and the generated directory listing may expose the full filesystem path in the HTML output. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6. | MEDIUM5.3 | 0.24%p15 | 2026-07-24 | |
| CVE-2026-34830 | Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Sendfile#map_accel_path interpolates the value of the X-Accel-Mapping request header directly into a regular expression when rewriting file paths for X-Accel-Redirect. Because the header value is not escaped, an attacker who can supply X-Accel-Mapping to the backend can inject regex metacharacters and control the generated X-Accel-Redirect response header. In deployments using Rack::Sendfile with x-accel-redirect, this can allow an attacker to cause nginx to serve unintended files from configured internal locations. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6. | HIGH7.5 | 0.23%p14 | 2026-07-24 | |
| CVE-2026-44587 | CarrierWave is a framework to upload files from Ruby applications. In versions prior to 2.2.7 and 3.1.3, the content_type_denylist check fails to escape regex metacharacters in string entries, causing the denylist to silently not match the content types it is intended to block. In lib/carrierwave/uploader/content_type_denylist.rb:57, denylist entries are interpolated directly into a regex without Regexp.quote or anchoring, so an entry such as image/svg+xml becomes the pattern /image\/svg+xml/, in which + is treated as a quantifier rather than a literal character and therefore never matches the real MIME type image/svg+xml. This is inconsistent with the allowlist implementation, which correctly applies both Regexp.quote and a \A anchor. Other content types containing regex metacharacters, such as application/xhtml+xml, are affected as well. As a result, any application that relies on content_type_denylist to block image/svg+xml, most commonly to prevent stored XSS, is silently unprotected. An attacker can upload an SVG file containing arbitrary JavaScript; if the application serves that SVG inline from its own origin, the script executes in the victim's browser, resulting in stored XSS. This issue has been fixed in versions 2.2.7 and 3.1.3. | MEDIUM6.1 | 0.22%p13 | 2026-10-25 | |
| CVE-2026-37737 | sanic-cors version 2.2.0 and prior contains an improper regular expression in the try_match() function in sanic_cors/core.py that uses re.match without end-anchoring. This allows an attacker to bypass CORS origin allowlists by registering a domain that begins with a trusted origin string, to gain unauthorized access to cross-origin requests for authenticated resources. | MEDIUM6.5 | 0.16%p6 | 2026-07-17 | |
| CVE-2026-34157 | # Security Vulnerability Report: Wails v2 — Origin Validator Bypass via Wildcard Pattern | | | |---|---| | **Product** | wailsapp/wails (v2) | | **Affected File** | `v2/internal/frontend/originvalidator/originValidator.go` | | **Affected Versions** | All versions containing originValidator (latest as of 2026-03-26) | | **CVSSv4.0** | **7.6 HIGH** — `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N` | | **CWE** | CWE-625: Permissive Regular Expression | | **Platforms** | Windows / Linux / macOS (all desktop targets) | --- ## Summary Wails v2 provides `BindingsAllowedOrigins` to restrict which web origins can invoke Go backend methods via IPC. The wildcard pattern matching in `wildcardPatternToRegex` converts `*` to `.*` without anchoring subcomponents, allowing suffix-matched origins to bypass the restriction. An attacker who controls a domain sharing a prefix with the allowed origin (e.g., `myapp.community` when `myapp.com*` is configured) can invoke arbitrary bound Go methods, potentially achieving file system access, data exfiltration, or code execution depending on the application's exposed API surface. --- ## Vulnerability Details ### Root Cause `wildcardPatternToRegex` converts a wildcard pattern to a regular expression by escaping special characters and replacing `*` with `.*`. The substituted `.*` has no restriction — it matches any character sequence including dots and additional domain components. ### Vulnerable Code **File:** `v2/internal/frontend/originvalidator/originValidator.go` ```go func (v *OriginValidator) wildcardPatternToRegex(wildcardPattern string) string { specialChars := []string{"\\", ".", "+", "?", "^", "$", "{", "}", "(", ")", "|", "[", "]"} escaped := wildcardPattern for _, specialChar := range specialChars { escaped = strings.ReplaceAll(escaped, specialChar, "\\"+specialChar) } // * becomes .* — matches ANY character sequence, including dots and domain separators escaped = strings.ReplaceAll(escaped, "*", ".*") return "^" + escaped + "$" } ``` The generated regex for `https://myapp.com*` is: ``` ^https://myapp\.com.*$ ``` This matches any string beginning with `https://myapp.com`, including: - `https://myapp.community` — different TLD - `https://myapp.com.attacker.com` — attacker-controlled subdomain - `https://myapp.comXXXXX` — any arbitrary suffix ### Scope Note The official comment in `options.go` gives `https://*.myapp.com` as the example pattern (subdomain prefix wildcard). This pattern is **not affected**. The vulnerability only manifests when developers use a trailing wildcard (`myapp.com*`), which is a natural misuse when intending to permit a domain and all its subpaths or ports. --- ## Impact Any Go method registered with Wails bindings becomes callable from the attacker's origin. Depending on the application: - File system read / write (common in desktop apps) - Database queries - OS command execution (if exposed via bindings) - Sensitive configuration or credential access --- ## Fix **PR:** https://github.com/wailsapp/wails/pull/5074 Wildcards are now only expanded when they represent a full domain component (immediately after `://`, `.`, or `:`). A wildcard appended to a partial label (e.g. `com*`) is stripped, preventing suffix-based bypasses. Comprehensive test suite added. --- ## Disclosure Timeline | Date | Event | |---|---| | 2026-03-26 | Vulnerability discovered during source code audit by @Saku0512 | | 2026-03-26 | Private report submitted via GitHub Security Advisory | | 2026-03-26 | Vendor acknowledgement and fix PR opened (#5074) | | TBD | Patch release | | TBD + 90 days | Public disclosure deadline | | NONE | no EPSS | PoC | 2026-10-27 |