CVE-2026-44882
HighCVSS 8.1Exploitation Probability (EPSS)
Low risk26th percentile - higher than 26% of all known CVEs
Summary
In Portainer Community Edition from version 2.33.0 to 2.33.7, there is a vulnerability due to a missing return statement after a token validation error in the kubeClientMiddleware layer. This causes a request with an invalid token to be forwarded to the Kubernetes cluster, bypassing authorization checks.
Risk Assessment
An attacker with a valid Portainer session but without permissions to a specific Kubernetes endpoint can gain unauthorized access to the cluster, potentially leading to data leakage or unauthorized operations on resources.
Recommendation
Immediately update Portainer to version 2.33.8 or later, which includes a fix for the missing return statement after token validation failure.
Other vulnerabilities in Portainer
See all- CVE-2026-44881Critical
Portainer Community Edition from version 2.33.0 to 2.33.8, 2.39.2, and 2.41.0 contains a vulnerability where, during creation or update of Git-backed stacks, go-git v5 creates OS symlinks on the host filesystem without validation, except for .gitmodules. An authenticated user with rights to manage Git stacks can include a docker-compose.yml file as a symlink to an arbitrary path, causing the GET /api/stacks/{id}/file endpoint to read and return the symlink target's contents in the HTTP response.
- CVE-2026-44885Medium
A vulnerability in Portainer Community Edition from version 2.33.0 to 2.33.7 allows writing files to arbitrary locations on the server filesystem via a crafted .tar.gz archive. The ExtractTarGz function does not prevent directory traversal, enabling overwriting of critical system files.
- CVE-2026-44883High
Portainer Community Edition versions 2.33.0 through 2.33.8, 2.39.2, and 2.41.0 accept JWT tokens via the ?token= URL parameter, leading to token leakage through proxy logs, browser history, and Referer headers. A leaked token grants full user privileges until expiration (default 8 hours).
- CVE-2026-44850High
Portainer Community Edition versions 2.33.0 through 2.33.7, 2.39.1, and 2.40.0 have a vulnerability in the Disable bind mounts security setting for non-administrators. The enforcement check only inspected the HostConfig.Binds array, ignoring the equivalent HostConfig.Mounts array, allowing authenticated users to mount arbitrary host paths into containers.
- CVE-2026-44849High
A vulnerability in Portainer Community Edition allows bypassing seven EndpointSecuritySettings restrictions when creating Docker Swarm services. These restrictions are enforced on the standard container creation path but not applied on the Swarm service API, enabling unprivileged users to launch containers with dangerous configurations.
- CVE-2026-44848High
In Portainer Community Edition versions 2.33.0 through 2.33.8, 2.39.2, and 2.41.0, the Docker plugin management endpoints (/plugins/*) were not registered with a handler. This allowed standard users with endpoint access to perform privileged plugin operations, including installing and enabling plugins, directly against the underlying Docker daemon.
Original NVD description (English source)
Portainer Community Edition is a lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, Kubernetes and ACI environments. From 2.33.0 to before 2.33., Portainer proxies requests to Kubernetes clusters through a middleware layer (kubeClientMiddleware) that validates the requesting user's token before forwarding traffic to the cluster. When security.RetrieveTokenData returned an error, the middleware wrote an HTTP 403 response but was missing a return statement — execution continued into the handler with a nil tokenData value. The Kubernetes endpoints sit behind Portainer's outer AuthenticatedAccess bouncer, so an attacker requires a valid Portainer session. However, a user whose secondary token validation fails in kubeClientMiddleware — for example a user without permission to access a given Kubernetes endpoint — would have their request forwarded to the cluster anyway, bypassing the authorization check. The same defect was present in both the CE and EE codebases. This vulnerability is fixed in 2.33.8.