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GHSA-hcwr-pq9g-rq3m

HIGH

GHSA-hcwr-pq9g-rq3m is a high-severity (CVSS 7.5) CWE-345 vulnerability in chainguard.dev/apko. O3 Security confirms whether GHSA-hcwr-pq9g-rq3m is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

apko doesn't verify downloaded apk packages against APKINDEX checksum (package substitution possible)

Also known asCVE-2026-42575GO-2026-5422
Published
May 4, 2026
Updated
Jun 25, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐹chainguard.dev/apko

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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 for discovering and reporting this issue.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐹Gochainguard.dev/apkoall versions1.2.7

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for chainguard.dev/apko. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update chainguard.dev/apko to 1.2.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hcwr-pq9g-rq3m is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-hcwr-pq9g-rq3m is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-hcwr-pq9g-rq3m. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 thank
O3 Security · Impact-Aware SCA

Is GHSA-hcwr-pq9g-rq3m in your dependencies?

O3 detects GHSA-hcwr-pq9g-rq3m across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.