What’s Vulnerable › Vulnerabilities

CVE-2026-42575: apko doesn't verify downloaded apk packages against APKINDEX checksum (package substitution possible)

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-09 · updated 2026-07-24
• Weakness: CWE-345

Description

apko allows users to build and publish OCI container images built from apk packages. Prior to version 1.2.7, 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. This issue has been patched in version 1.2.7.

Affected products

• chainguard-dev apko: before 1.2.7

References

• https://github.com/chainguard-dev/apko/commit/a118c3d604107532b5525bd4bee2fb369a6228aa
• https://github.com/chainguard-dev/apko/releases/tag/v1.2.7
• https://github.com/chainguard-dev/apko/security/advisories/GHSA-hcwr-pq9g-rq3m

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