CVE-2026-42574 apko dirFS has a symlink-following path traversal that allows multiple entry points to escape the build root
Attackers can escape the build root via symlink traversal in apko, potentially modifying host files or executing code during container image builds.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42574?
CVE-2026-42574 is a high-severity path traversal vulnerability in chainguard-dev apko, published on 9 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
apko allows users to build and publish OCI container images built from apk packages. From version 0.14.8 to before version 1.2.5, a crafted .apk could install a TypeSymlink tar entry whose target pointed outside the build root, and a subsequent directory-creation or file-write entry in the same or later archive could traverse that symlink to reach host paths the build user could write to. This issue has been patched in version 1.2.5.
Which versions are affected by CVE-2026-42574?
3 open source packages ship an affected version, including chainguard.dev/apko.
| Package | Affected | Fixed in |
|---|---|---|
chainguard.dev/apko Go | From 0.14.8 | 1.2.5 |
chainguard.dev/apko Go | From 0.14.8 | 1.2.5 |
chainguard.dev/apko Go | From 0.14.8 | 1.2.5 |
How do I fix CVE-2026-42574?
Upgrade chainguard.dev/apko to 1.2.5 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-42574 being exploited?
There is no known exploitation of CVE-2026-42574 in the wild and no public exploit code.
Sources
Also known as CLEANSTART-2026-PO41193, GHSA-qq3r-w4hj-gjp6, GO-2026-5589, MINI-9mqh-3x4q-f6gv.