Vulnerability in Chainguard-Dev Apko
CVE-2026-42575
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.
EPSS: 0.002 (5.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Chainguard-dev Apko — versions < 1.2.7
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-42575?
- CVE-2026-42575 is a high-severity vulnerability in Chainguard-Dev Apko, classified under Insufficient Verification of Data Authenticity. CVSS score: 7.5/10. Published 2026-05-09.
- How severe is CVE-2026-42575?
- High severity. CVSS v3 base score is 7.5 out of 10.