# CVE-2026-25121: GO-2026-4405 - apko has a path traversal in apko dirFS which allows filesystem writes outside base in chainguard.dev/apko

Source: https://junglewise.ai/threats/cve-2026-25121-apko-has-a-path-traversal-in-apko-dirfs-which-allows-filesystem  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-05  
License: CC BY 4.0 with a link back

CVE-2026-25121 · Severity: low · CVSS 3.1 · Published 2026-02-05

apko has a path traversal in apko dirFS which allows filesystem writes outside base in chainguard.dev/apko

Technologies: [chainguard.dev/apko (Go)](https://junglewise.ai/threats/technologies/chainguard-dev-apko). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-25121 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-25121 being exploited in the wild.

**How severe is CVE-2026-25121?** Low severity, with a CVSS score of 3.1, published 5 February 2026.

**Which products and versions are affected?** chainguard.dev/apko (Go) SEMVER:introduced=0.14.8,fixed=1.1.0.

**Is there a fix for CVE-2026-25121?** Yes. chainguard.dev/apko (Go): upgrade to 1.1.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-25121?** Check whether you run chainguard.dev/apko (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- chainguard.dev/apko (Go): upgrade to 1.1.0 or later

  ```sh
  go get chainguard.dev/apko@v1.1.0
  ```


## Affected products

- chainguard.dev/apko (Go) SEMVER:introduced=0.14.8,fixed=1.1.0

## Identifiers

- CVE-2026-25121
- GHSA-5g94-c2wx-8pxw
- GO-2026-4405

## Related threats

- [Chainguard Melange and Apko incomplete package integrity verification](https://junglewise.ai/threats/cve-2026-54174-chainguard-melange-and-apko-incomplete-package-integrity)
- [Chainguard apko denial of service via incorrect type assertion in DiscoverKeys](https://junglewise.ai/threats/cve-2026-42576-chainguard-apko-denial-of-service-via-incorrect-type-assertion-in)
- [Chainguard apko insufficient integrity check for apk packages](https://junglewise.ai/threats/cve-2026-42575-chainguard-apko-insufficient-integrity-check-for-apk-packages)
- [Chainguard apko path traversal via symlink following in DirFS](https://junglewise.ai/threats/cve-2026-42574-chainguard-apko-path-traversal-via-symlink-following-in-dirfs)
- [GO-2026-4410 - apko affected by potential unbounded resource consumption in expandapk.ExpandApk on attacker-controlled…](https://junglewise.ai/threats/cve-2026-25140-go-2026-4410-apko-affected-by-potential-unbounded-resource)