melange affected by potential host command execution via license-check YAML mode patch pipeline
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. Fix: Fixed in [bd132535](https://github.com/chainguard-dev/melange/commit/bd132535cd9f57d4bd39d9ead0633598941af030) , Released in 0.40.3. Acknowledgements melange thanks Oleh Konko (@1seal) from 1seal for discovering and reporting this issue.
02 / AFFECTED SOFTWARE
Affected packages
163 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
melange affected by potential host command execution via license-check YAML mode patch pipeline in chainguard.dev/melange
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. Fix: Fixed in [bd132535](https://github.com/chainguard-dev/melange/commit/bd132535cd9f57d4bd39d9ead0633598941af030) , Released in 0.40.3. Acknowledgements melange thanks Oleh Konko (@1seal) from 1seal for discovering and reporting this issue.
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.
05 / REFERENCES
Further evidence
- https://github.com/chainguard-dev/melange/commit/bd132535cd9f57d4bd39d9ead0633598941af030
- https://github.com/chainguard-dev/melange/security/advisories/GHSA-rf4g-89h5-crcr
- https://nvd.nist.gov/vuln/detail/CVE-2026-25143
- https://github.com/chainguard-dev/melange
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25143.json