Security Digest · Vulnerability record
CVE-2026-41050: Fleet: Helm impersonation bypass of `RESTClientGetter` retains `cluster-admin` during template rendering
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.
CVSS 9.9 Critical EPSS 0.4% · p37
Should you act?
Critical, preconditions apply
Severe if exploited, but exploitation needs conditions that may not apply to you. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.4%, percentile 37: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 37% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes
github.com/rancher/fleet(Go) >= 0.15.0, < 0.15.1, fixed in 0.15.1;github.com/rancher/fleet(Go) >= 0.14.0, < 0.14.5, fixed in 0.14.5;github.com/rancher/fleet(Go) >= 0.13.0, < 0.13.10, fixed in 0.13.10;github.com/rancher/fleet(Go) >= 0.12.0, < 0.12.14, fixed in 0.12.14. Check your lockfile, including transitive dependencies.
What it is
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.
From the GitHub advisory
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.
Weakness type: CWE-863.
Product: github.com/rancher/fleet (Go) · Assigned by: suse · Published: 2026-05-13
Affected and fixed versions
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | github.com/rancher/fleet | >= 0.15.0, < 0.15.1 | 0.15.1 |
| Go | github.com/rancher/fleet | >= 0.14.0, < 0.14.5 | 0.14.5 |
| Go | github.com/rancher/fleet | >= 0.13.0, < 0.13.10 | 0.13.10 |
| Go | github.com/rancher/fleet | >= 0.12.0, < 0.12.14 | 0.12.14 |
| Go | github.com/rancher/fleet | >= 0.11.0, < 0.11.13 | 0.11.13 |
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| SUSE | Rancher | 0.15.0 < 0.15.1, 0.14.0 < 0.14.5, 0.13.0 < 0.13.10, 0.12.0 < 0.12.14, 0.11.0 < 0.11.13 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| suse | 3.1 | 9.9 Critical | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| GitHub | 3.1 | 9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: low (any account)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 0.44% probability of exploitation activity in the next 30 days; percentile 37.
Timeline
- — GitHub-reviewed advisory GHSA-765j-qfrp-hm3j published (critical)
- — CVE record published by suse
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vulnerability records
- GitHub Advisory GHSA-765j-qfrp-hm3j github.com
- CVE.org record CVE-2026-41050 cve.org
- NVD entry CVE-2026-41050 nvd.nist.gov
Other references from the CVE record and advisory
- bugzilla.suse.com bugzilla.suse.com
- github.com github.com