# CVE-2026-123373: compose-lint: A committed symlink makes compose-lint quote a file from outside the project into its output


- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 9 Nov 2026
- **Updated:** 9 Nov 2026
- **Also known as:** GHSA-whr6-fgpq-fpv9

## What is CVE-2026-123373?

CVE-2026-123373 is a low-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. From 0.2.0 until 0.25.0, compose-lint follows a project-controlled symbolic link used as the Compose file outside the project. The same issue affects compose.override.yml and a COMPOSE_FILE entry from 0.22.0, and an env_file target from 0.23.0. If an external Compose-related target fails YAML parsing, the error quotes an attacker-uncontrolled line into standard error, JSON errors, and SARIF notifications, while an external env_file can expose credential-like key names through CL-0020 and CL-0021 findings. The attacker selects the target path but not the exact parser-failure line, values from env_file are not printed, and the pass or fail result is unchanged. This issue is fixed in version 0.25.0.

Weakness: CWE-59 (Improper Link Resolution Before File Access), CWE-209 (Generation of Error Message Containing Sensitive Information)

## Which versions are affected by CVE-2026-123373?

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 | 0.25.0 |
| `compose-lint` | PyPI | From 0.2.0 | 0.25.0 |

## How do I fix CVE-2026-123373?

Upgrade tmatens/compose-lint to 0.25.0 or later.

## Is CVE-2026-123373 being exploited?

There is no known exploitation of CVE-2026-123373 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-123373 and fix it if it is affected.

What it is: CVE-2026-123373 is a low-severity vulnerability in tmatens compose-lint, published on 9 Nov 2026. 
Exploitation: There is no known exploitation of CVE-2026-123373 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 0.25.0
- compose-lint (PyPI): affected from 0.2.0; fixed in 0.25.0

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-2026-123373/ (Markdown: https://insights.sbomify.com/CVE-2026-123373/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-123373
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123373
- OSV: https://osv.dev/vulnerability/CVE-2026-123373

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-123373/
Summaries are generated and may contain mistakes; the official description above is the record.