GHSA-hcwr-pq9g-rq3m
apko doesn't verify downloaded apk packages against APKINDEX checksum (package substitution possible)
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | chainguard.dev/apko | < 1.2.7 | 1.2.7 |
Details
As written in the advisory (Markdown source, shown as plain text).
apko verifies the signature on `APKINDEX.tar.gz` but never compares individually downloaded `.apk` packages against the checksum recorded in the signed index. The checksum is parsed and available via `ChecksumString()`, and the downloaded package control hash is computed, but the two values are never compared in `getPackageImpl()`. Mismatched packages are silently accepted. An attacker who can substitute download responses (compromised mirror, HTTP repository, poisoned CDN cache) can install arbitrary packages into built images.
**Fix:** No fix available yet.
**Acknowledgements**
apko thanks Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/chainguard-dev/apko/security/advisories/GHSA-hcwr-pq9g-rq3m
- https://nvd.nist.gov/vuln/detail/CVE-2026-42575
- https://github.com/chainguard-dev/apko/commit/a118c3d604107532b5525bd4bee2fb369a6228aa
- https://github.com/chainguard-dev/apko
- https://github.com/chainguard-dev/apko/releases/tag/v1.2.7