CVE-2026-25143: chainguard-dev melange OS Command Injection

Vulnerability summary

CVE-2026-25143 is a high (CVSS 7.8) OS Command Injection vulnerability in chainguard-dev melange. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.5% of scored vulnerabilities.

Timeline

1. 04-02-2026
   PublishedVulnerability first disclosed.
2. 05-02-2026
   Last modifiedVulnerability information updated.

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.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.