---
id: "CVE-2026-123370"
page: "https://infrastack.ai/live/CVE-2026-123370"
kind: "vulnerability"
aliases: ["CVE-2026-123370"]
title: "compose-lint: line-break handling bug lets a pull request delete config lines"
severity: "medium"
cvss: 5.1
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ci", "compose-lint", "docker-compose", "package"]
not_affected_if: ["check-only-usage", "version-0.18.0-or-later"]
published_at: "2026-11-09T18:17:25+00:00"
first_seen_at: "2026-11-09T18:27:56+00:00"
updated_at: "2026-11-09T18:29:21+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-123370", "first_seen_at": "2026-11-09T18:27:56+00:00"}]
exploit_sources: []
---

# compose-lint: line-break handling bug lets a pull request delete config lines

Link for people: https://infrastack.ai/live/CVE-2026-123370 (this .md is for agents)

compose-lint is a linter for Docker Compose files that flags risky settings. A crafted pull request can place a special line-break character in a quoted value, so the fix --apply command deletes an unrelated line after the target, possibly removing a network or security setting.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed compose-lint version with `compose-lint --version` or the package manifest; versions before `0.18.0` from `0.9.0` are affected.
- Look in CI pipelines for compose-lint running `fix --apply` against files from pull requests.

## Fix

- compose-lint: move to `0.18.0`

## Timeline

- 2026-11-09T18:27:56+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-123370

## Documents

- [advisory] Vendor advisory: github.com https://github.com/tmatens/compose-lint/security/advisories/GHSA-65v8-q222-64xx
- [fix] Patch: github.com https://github.com/tmatens/compose-lint/commit/c9d453a6a69c076788fe1db05cb54684a616d1de
- [fix] Patch: github.com https://github.com/tmatens/compose-lint/commit/cbbf886d91347dea9c51b584eb50088e70007d0d
- [fix] Release notes: github.com https://github.com/tmatens/compose-lint/releases/tag/v0.18.0

## From the sources

compose-lint is a Docker Compose security linter that identifies dangerous misconfigurations before deployment. From 0.9.0 until 0.18.0, compose-lint's YAML parser recognizes lone carriage returns and Unicode line separators U+0085, U+2028, and U+2029 as line breaks while fix position conversion counts only newline characters. A pull request can place one of these separators in a quoted value so fix --apply shifts each later edit and deletes the line after the selected target, including an unselected network or other security setting. The resulting Compose file can remain valid, post-edit checks can pass, and the command can report a successful fix even though the dry-run diff was the only place showing the extra deletion. This issue is fixed in version 0.18.0.

---

_Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai_