chainguard-dev/apko · Security
apko has a path traversal in apko dirFS which allows filesystem writes outside base
- GHSA ID
- GHSA-5g94-c2wx-8pxw
- CVE ID
- CVE-2026-25121
- Severity
- high
- Published
- Updated
- CVSS
- 7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CVSS v3
- 7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Description
A Path Traversal vulnerability was discovered in apko's dirFS filesystem abstraction. An attacker who can supply a malicious APK package (e.g., via a compromised or typosquatted repository) could create directories or symlinks outside the intended installation root. The MkdirAll, Mkdir, and Symlink methods in pkg/apk/fs/rwosfs.go use filepath.Join() without validating that the resulting path stays within the base directory.
Fix: Fixed by d8b7887. Merged into release.
Acknowledgements
apko thanks Oleh Konko from 1seal for discovering and reporting this issue.
CWEs
- CWE-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
- CWE-23 · Relative Path Traversal