Technical impact
The vulnerability allows a tenant with git push capability to a Fleet‑monitored repository to exploit a bypass in the Helm deployer's ServiceAccount impersonation logic. The impersonated identity retains cluster‑admin privileges during template rendering, permitting the attacker to read any secret in any namespace across all downstream clusters targeted by that GitRepo. This reflects an authorization flaw identified as CWE‑863, leading to the unauthorized disclosure of highly sensitive configuration data.
Affected Systems
The affected product is Rancher’s Fleet Helm deployment component. No specific version numbers are disclosed, but the issue applies to any configuration using Fleet to deploy Helm charts from Git repositories.
Risk and Exploitability
The CVSS score of 9.9 marks this issue as Critical. While EPSS data is not available and the vulnerability is not listed in CISA’s KEV catalog, the high severity and the potential to read secrets from any namespace make the risk significant. The likely attack vector involves a malicious commit in a Git repository that Fleet watches; if not mitigated, attackers can retrieve secrets from any cluster namespace.
Github GHSA