CVE-2026-23634

Pepr is a type safe K8s middleware. Prior to 1.0.5 , Pepr defaults to a cluster-admin RBAC configuration and does not explicitly force or enforce least-privilege guidance for module authors. The default behavior exists to make the “getting started” experience smooth: new users can experiment with Pepr and create resources dynamically without needing to pre-configure RBAC. This vulnerability is fixed in 1.0.5.

Pepr is a type safe K8s middleware. Prior to 1.0.5 , Pepr defaults to a cluster-admin RBAC configuration and does not explicitly force or enforce least-privilege guidance for module authors. The default behavior exists to make the “getting started” experience smooth: new users can experiment with Pepr and create resources dynamically without needing to pre-configure RBAC. This vulnerability is fixed in 1.0.5.

Severity: LOW Target: /workspace/pepr/src/lib/assets/rbac.ts Endpoint: Kubernetes RBAC configuration Method: Deployment ## Response / Rationale Pepr defaults to `rbacMode: "admin"` because the initial experience is designed to be frictionless for new users. This mode ensures that users can deploy and run the default `hello-pepr.ts` module without needing to understand or pre-configure RBAC rules. It’s important to note that `hello-pepr.ts` is intended strictly as a demo to showcase Pepr features and workflow. It is not intended for production use, and the documentation explicitly calls out that admin RBAC should not be used in production environments. That said, if a user skips the documentation and does not review the `npx pepr build` options, they could deploy a module with broader privileges than necessary. We consider this low severity because Pepr is a framework: the module author is ultimately responsible for selecting the appropriate RBAC scope for their module and environment as each module has different RBAC needs and requirements. Our security focus is on ensuring the Pepr controller and runtime components operate securely within Kubernetes, while still allowing developers the flexibility to build modules with the access they require. In order to fix this we will warn the user in logs that the default `ClusterRole` is `cluster-admin` and that it is not recommended for production. ## How this can be exploited This is not an inherently exploitable CVE in the traditional sense. It is being flagged because Pepr defaults to a cluster-admin RBAC configuration and does not explicitly force or enforce least-privilege guidance for module authors. The default behavior exists to make the “getting started” experience smooth: new users can experiment with Pepr and create resources dynamically without needing to pre-configure RBAC. Remediation: scope RBAC appropriately before deploying to production. Running: ```bash npx pepr build --rbac-mode=scoped ``` generates the minimum RBAC required for the controller/informer to watch resources. Any additional permissions must be added based on the specific Kubernetes resources and CRUD operations performed by the module

Severity: LOW Target: /workspace/pepr/src/lib/assets/rbac.ts Endpoint: Kubernetes RBAC configuration Method: Deployment ## Response / Rationale Pepr defaults to `rbacMode: "admin"` because the initial experience is designed to be frictionless for new users. This mode ensures that users can deploy and run the default `hello-pepr.ts` module without needing to understand or pre-configure RBAC rules. It’s important to note that `hello-pepr.ts` is intended strictly as a demo to showcase Pepr features and workflow. It is not intended for production use, and the documentation explicitly calls out that admin RBAC should not be used in production environments. That said, if a user skips the documentation and does not review the `npx pepr build` options, they could deploy a module with broader privileges than necessary. We consider this low severity because Pepr is a framework: the module author is ultimately responsible for selecting the appropriate RBAC scope for their module and environment as each module has different RBAC needs and requirements. Our security focus is on ensuring the Pepr controller and runtime components operate securely within Kubernetes, while still allowing developers the flexibility to build modules with the access they require. In order to fix this we will warn the user in logs that the default `ClusterRole` is `cluster-admin` and that it is not recommended for production. ## How this can be exploited This is not an inherently exploitable CVE in the traditional sense. It is being flagged because Pepr defaults to a cluster-admin RBAC configuration and does not explicitly force or enforce least-privilege guidance for module authors. The default behavior exists to make the “getting started” experience smooth: new users can experiment with Pepr and create resources dynamically without needing to pre-configure RBAC. Remediation: scope RBAC appropriately before deploying to production. Running: ```bash npx pepr build --rbac-mode=scoped ``` generates the minimum RBAC required for the controller/informer to watch resources. Any additional permissions must be added based on the specific Kubernetes resources and CRUD operations performed by the module

Pepr es un middleware de K8s con seguridad de tipos. Antes de la versión 1.0.5, Pepr se configura por defecto con una configuración RBAC de cluster-admin y no fuerza ni impone explícitamente directrices de mínimo privilegio para los autores de módulos. Este comportamiento predeterminado existe para que la experiencia de 'primeros pasos' sea fluida: los nuevos usuarios pueden experimentar con Pepr y crear recursos dinámicamente sin necesidad de preconfigurar RBAC. Esta vulnerabilidad se corrige en la versión 1.0.5.