# CVE-2026-125121: compose-lint: Text in a pull request can still issue CI workflow commands through compose-lint 0.31.0's output


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 10 Nov 2026
- **Updated:** 12 Nov 2026
- **Also known as:** GHSA-r7j4-crjv-h467

## What is CVE-2026-125121?

CVE-2026-125121 is a medium-severity vulnerability in tmatens compose-lint, published on 10 Nov 2026. 

### Official description

compose-lint is a Docker Compose security linter that identifies dangerous misconfigurations before deployment. In version 0.31.0, compose-lint escapes GitHub Actions workflow-command openers only after ASCII spaces and tabs, while the runner strips all leading Unicode whitespace before interpreting a line. Untrusted Compose values or repository paths beginning with Unicode whitespace followed by :: can therefore reach the text report, fix guidance, the fix dry-run diff, and stderr diagnostics as workflow commands when the package, pre-commit hook, or Docker image runs directly in CI. The GitHub Action is not affected because it disables command processing, and the flaw does not change the lint pass or fail result. This issue is fixed in version 0.32.0.

Weakness: CWE-150 (Improper Neutralization of Escape, Meta, or Control Sequences), CWE-117 (Improper Output Neutralization for Logs)

## Which versions are affected by CVE-2026-125121?

1 open source package ship an affected version, including compose-lint.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `compose-lint` | PyPI | From 0.31.0 | 0.32.0 |

## How do I fix CVE-2026-125121?

Upgrade compose-lint to 0.32.0 or later.

## Is CVE-2026-125121 being exploited?

There is no known exploitation of CVE-2026-125121 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-125121 and fix it if it is affected.

What it is: CVE-2026-125121 is a medium-severity vulnerability in tmatens compose-lint, published on 10 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-125121 in the wild and no public exploit code.

Affected packages and fixed versions:
- compose-lint (PyPI): affected from 0.31.0; fixed in 0.32.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-125121/ (Markdown: https://insights.sbomify.com/CVE-2026-125121/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-125121
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-125121
- OSV: https://osv.dev/vulnerability/CVE-2026-125121

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-125121/
Summaries are generated and may contain mistakes; the official description above is the record.