apko is vulnerable to path traversal in apko dirFS which allows filesystem writes outside base
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.
Summary
apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before 1.1.1, 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. This issue has been patched in version 1.1.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| chainguard-dev | apko | 0.14.8 to before 1.1.1 | 1.1.1 | Patch available | CNA |
| — | chainguard.dev/apko (Go) | 0.14.8 to before 1.1.0 | 1.1.0 | Patch available | GHSA-5g94-c2wx-8pxw |
- apko Vendorchainguard-dev Affected 0.14.8 to before 1.1.1 Fixed in 1.1.1 Patch available CNA
- chainguard.dev/apko (Go) Vendor— Affected 0.14.8 to before 1.1.0 Fixed in 1.1.0 Patch available GHSA-5g94-c2wx-8pxw
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:chainguard:apko:*:*:*:*:*:go:*:* | 0.14.8 to before 1.1.1 | Vulnerable | chainguard-dev |
- cpe:2.3:a:chainguard:apko:*:*:*:*:*:go:*:* Versions 0.14.8 to before 1.1.1 Vulnerable ·chainguard-dev
Remediation
- Fix · CNA apko (chainguard-dev) Fixed in 1.1.1
- Fix · GHSA-5g94-c2wx-8pxw chainguard.dev/apko (Go) Fixed in 1.1.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-25121
- 2026-10-03 Alias added: GHSA-5g94-c2wx-8pxw
References
More chainguard-dev Apko vulnerabilities
- TI-2026-20302 apko affected by potential unbounded resource consumption in expandapk.ExpandApk on attacker-controlled .apk streams CVSS 3.1HIGH 7.5
- TI-2026-20285 apko is vulnerable to unbounded resource consumption in expandapk.Split on attacker-controlled .apk streams CVSS 3.1MEDIUM 5.5
Sources
- CVE-2026-25121 · CVE Program
- CVE-2026-25121 · NVD
- FIRST EPSS
- GHSA-5g94-c2wx-8pxw · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences