Mesa is an open‑source Python library. In versions 3.5.0 and earlier, the benchmarks.yml workflow could be manipulated to execute arbitrary code in a privileged GitHub Actions runner. The flaw is a classic code injection error (CWE‑94). This allows an attacker to run malicious commands with the permissions of the runner, creating a full compromise of the CI environment.

The vulnerability affects the Mesa library (mesa:mesa) versions 3.5.0 and older. All installations that rely on these versions and use the benchmarks.yml CI workflow are susceptible. The issue was resolved by commit c35b8cd, so newer releases are not affected.

The CVSS score is 8.3, reflecting high severity. The EPSS score is less than 1 %, indicating low probability of widespread exploitation at present, and the vulnerability is not listed in CISA’s KEV catalog. Attackers would need to supply untrusted code checked out by the benchmarks.yml workflow, but the vulnerability can be triggered directly in a privileged runner without additional prerequisites. Until a patch is applied, the risk remains high for CI environments that run the workflow.