MesaApplication · Mesa Project
CVE-2026-29075
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedMesa 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceMesa versions 3.5.0 and prior contain a vulnerability in the benchmarks.yml GitHub Actions workflow where checking out untrusted code can lead to arbitrary code execution in a privileged CI/CD runner. An attacker could exploit this by submitting malicious code that gets executed during workflow runs, potentially compromising the build infrastructure.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
MesaApplication
<= 3.5.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Mesa versionRun 'pip show mesa' or check your installed mesa package version using your package manager. Compare against the affected range: versions 3.5.0 and prior.Affected if Installed version is 3.5.0 or lower (or if you cannot determine the version and are using an older Mesa installation).
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Locate benchmarks.yml workflow fileNavigate to the .github/workflows/ directory in your Mesa repository and verify if a file named benchmarks.yml exists.Affected if The benchmarks.yml file exists in the repository's GitHub Actions workflows.
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Inspect workflow for untrusted code checkoutOpen the benchmarks.yml file and examine all 'uses' statements or 'run' commands that execute git operations. Look for patterns like 'actions/checkout' with untrusted repositories, external workflow calls, or any checkout of code from untrusted sources.Affected if The workflow contains actions that checkout code from untrusted or external repositories without proper review, or runs commands that execute untrusted code in the CI environment.
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Verify workflow runs with elevated privilegesCheck if the benchmarks.yml workflow runs with elevated permissions (such as write-all or admin privileges) by examining the 'permissions' section at the workflow or job level.Affected if The workflow has broad write permissions (such as permissions: write-all) and processes external or untrusted code.
You are affected if your Mesa installation version is 3.5.0 or lower AND your repository contains a benchmarks.yml workflow that executes untrusted code in a privileged CI/CD context.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpdate to a Mesa version newer than 3.5.0 which contains the patch from commit c35b8cd, or manually review and harden the benchmarks.yml workflow to avoid checking out untrusted external code.
Apply the security fix from commit c35b8cd67fc89dd680ae218e49b77f6e1ee07a27 to your benchmarks.yml workflow; the next Mesa release after 3.5.0 will include this fix
- 1. Navigate to the repository's .github/workflows directory
- 2. Locate the benchmarks.yml workflow file
- 3. Review the changes in commit c35b8cd67fc89dd680ae218e49b77f6e1ee07a27 to understand the security fix applied
- 4. Apply the same fix to your local benchmarks.yml file - typically this involves using `persist-credentials: false` on the actions/checkout step for untrusted code, or adding additional safeguards when checking out pull request code from forks
- 5. Commit the patched workflow file to your repository
- 6. Test the workflow to ensure it still functions correctly after the security changes
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Mesa
Scoped from the published advisory
- Consultation2.0 h
- Implementation1.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-29075 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-29075 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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