Vulnerability · Published Feb 4, 2026 · Assigned by GitHub_M
CVE-2026-25121apko is vulnerable to path traversal in apko dirFS which allows filesystem writes outside base
High 7.5
In plain English
A high-severity security flaw in apko from chainguard-dev. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | chainguard.dev/apko | 1.1.0 | GHSA-5g94-c2wx-8pxw |
| Go | chainguard.dev/apko | 1.1.0 | GO-2026-4405 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| chainguard-dev | apko | >= 0.14.8, < 1.1.1 |
Weakness: CWE-23 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N