# CVE-2026-123369: compose-lint: Compose file text can issue GitHub Actions workflow commands through the compose-lint Action


- **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:** 9 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-6f4g-xm8v-pgv6

## What is CVE-2026-123369?

CVE-2026-123369 is a medium-severity vulnerability in tmatens compose-lint, published on 9 Nov 2026. 

### Official description

compose-lint is a Docker Compose security linter that identifies dangerous misconfigurations before deployment. Prior to 0.31.0, compose-lint prints attacker-controlled service names, environment keys, file lines, and other Compose text without neutralizing GitHub Actions and Azure Pipelines workflow-command openers. When a workflow processes a pull request, legacy ##[ commands or a line-leading double-colon command can create false annotations, hide log regions, mask selected strings, or invoke other commands recognized by the runner. The affected text report paths do not alter the compose-lint exit code or pass or fail result, but they can misrepresent the CI output presented to reviewers. This issue is fixed in version 0.31.0.

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

## Which versions are affected by CVE-2026-123369?

2 open source packages ship an affected version, including tmatens/compose-lint and compose-lint.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `tmatens/compose-lint` | GitHub Actions | From 0.2.0 | 0.31.0 |
| `compose-lint` | PyPI | All versions | 0.31.0 |

## How do I fix CVE-2026-123369?

Upgrade tmatens/compose-lint to 0.31.0 or later.

## Is CVE-2026-123369 being exploited?

There is no known exploitation of CVE-2026-123369 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123369 and fix it if it is affected.

What it is: CVE-2026-123369 is a medium-severity vulnerability in tmatens compose-lint, published on 9 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123369 in the wild and no public exploit code.

Affected packages and fixed versions:
- tmatens/compose-lint (GitHub Actions): affected from 0.2.0; fixed in 0.31.0
- compose-lint (PyPI): affected all versions; fixed in 0.31.0

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-2026-123369/ (Markdown: https://insights.sbomify.com/CVE-2026-123369/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123369
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123369
- OSV: https://osv.dev/vulnerability/CVE-2026-123369

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123369/
Summaries are generated and may contain mistakes; the official description above is the record.