Summary
Fleet: Helm impersonation bypass of RESTClientGetter retains cluster-admin during template rendering
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
GitRepoRestrictionresources 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
lookupcalls andfleet.yamlfiles for cross-namespacevaluesFromreferences as a detective control.
Resources
If there are any questions or comments about this advisory:
- Reach out to the SUSE Rancher Security team for security related inquiries.
- Open an issue in the Rancher repository.
- Verify using the support matrix and product support lifecycle.
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 for further information about this category of attack.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
CVE-2026-41050 has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.15.1, 0.14.5, 0.13.10, 0.12.14, 0.11.13); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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 versionv0.11.13.
Frequently Asked Questions
- What is CVE-2026-41050? CVE-2026-41050 is a critical-severity incorrect authorization vulnerability in github.com/rancher/fleet (go), affecting versions >= 0.15.0, < 0.15.1. It is fixed in 0.15.1, 0.14.5, 0.13.10, 0.12.14, 0.11.13. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- How severe is CVE-2026-41050? CVE-2026-41050 has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/rancher/fleet are affected by CVE-2026-41050? github.com/rancher/fleet (go) versions >= 0.15.0, < 0.15.1 is affected.
- Is there a fix for CVE-2026-41050? Yes. CVE-2026-41050 is fixed in 0.15.1, 0.14.5, 0.13.10, 0.12.14, 0.11.13. Upgrade to this version or later.
- Is CVE-2026-41050 exploitable, and should I be worried? Whether CVE-2026-41050 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-41050 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-41050?
- Upgrade
github.com/rancher/fleetto 0.15.1 or later - Upgrade
github.com/rancher/fleetto 0.14.5 or later - Upgrade
github.com/rancher/fleetto 0.13.10 or later - Upgrade
github.com/rancher/fleetto 0.12.14 or later - Upgrade
github.com/rancher/fleetto 0.11.13 or later
- Upgrade