CVE-2026-41050

Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in Rancher Fleet Helm Deployer ausnutzen, um Sicherheitsvorkehrungen zu umgehen und vertrauliche Informationen offenzulegen, was möglicherweise weitere Angriffe ermöglicht.

### Impact Fleet's Helm deployer did not fully apply ServiceAccount impersonation in two code paths, allowing a tenant with git push access to a Fleet-monitored repository to read secrets from any namespace on every downstream cluster targeted by their `GitRepo`. **Helm `lookup` bypass:** The Helm template engine ran Kubernetes API queries with the fleet-agent's cluster-admin credentials instead of the impersonated ServiceAccount. A chart template could therefore access resources beyond the tenant's RBAC scope. **`valuesFrom` bypass:** Secret and ConfigMap references in `fleet.yaml` `helm.valuesFrom` were read using the fleet-agent's cluster-admin client. A tenant could reference resources in namespaces the impersonated ServiceAccount has no access to. Both issues break Fleet's multi-tenant impersonation boundary. The leaked credentials may belong to external services, making the full impact non-deterministic. Single-tenant deployments where all users are trusted are not affected. **Important:** - For the exposure of additional credentials, the final impact severity for confidentiality, integrity and availability is dependent on the permissions the leaked credentials have on their services. - It is recommended to review for potentially leaked credentials in this scenario and to change them if deemed necessary. Please consult the associated [MITRE ATT&CK - Technique - Account Access Removal](https://attack.mitre.org/techniques/T1531/) for further information about this category of attack. ### Patches Both issues are fixed by ensuring the Helm action configuration consistently uses the impersonated ServiceAccount credentials throughout all Helm operations. Patched versions of Rancher include releases `v2.14.1`, `v2.13.5`, `v2.12.9`, and `v2.11.13`. For Rancher `v2.10.11`, users must manually update their Fleet deployment to version`v0.11.13`. ### Workarounds No workaround fully mitigates the issue for multi-tenant deployments. The patches should be applied as soon as they are available. The following measures reduce the attack surface but do not close either vulnerability: - Restrict git push access to Fleet-monitored repositories to trusted users only. In a multi-tenant setup this removes the precondition entirely, but is often not operationally viable. - Use `GitRepoRestriction` resources to limit which ServiceAccounts each namespace is allowed to use, restricting the set of users who can configure impersonation at all. - Audit deployed chart templates for `lookup` calls and `fleet.yaml` files for cross-namespace `valuesFrom` references as a detective control. ### Resources If there are any questions or comments about this advisory: - Reach out to the [SUSE Rancher Security team](https://github.com/rancher/rancher/security/policy) for security related inquiries. - Open an issue in the [Rancher](https://github.com/rancher/rancher/issues/new/choose) repository. - Verify using the [support matrix](https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/) and [product support lifecycle](https://www.suse.com/lifecycle/).

Fleet: Helm impersonation bypass of `RESTClientGetter` retains `cluster-admin` during template rendering in github.com/rancher/fleet