CVE-2026-25121
apko has a path traversal in apko dirFS which allows filesystem writes outside base
Impact
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](https://github.com/chainguard-dev/apko/commit/d8b7887a968a527791b3c591ae83928cb49a9f14). Merged into release. **Acknowledgements** apko thanks Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | chainguard.dev/apko | >= 0.14.8, < 1.1.0 | 1.1.0 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Chainguard | Apko | from 0.14.8 before 1.1.1 |