CVE-2026-42575
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
apko, a tool for building OCI container images from apk packages, prior to version 1.2.7 verifies the signature on APKINDEX.tar.gz but never compares individually downloaded .apk packages against the checksum recorded in the signed index. An attacker who can substitute download responses (compromised mirror, HTTP repository, poisoned CDN cache) can install arbitrary packages into built images.
Risk Assessment
An attacker can inject malicious packages into container images, potentially compromising environments where those images are run.
Recommendation
Immediately update apko to version 1.2.7 or later, which contains the fix.
Other vulnerabilities in apko
See all- CVE-2026-42576Medium
In apko prior to version 1.2.7, the DiscoverKeys function in pkg/apk/apk/implementation.go unconditionally type-asserts JWKS keys as *rsa.PublicKey without checking the key type. If a repository JWKS endpoint returns a non-RSA key (e.g., EC), the unchecked assertion panics and crashes apko. This affects any workflow that initializes the APK database and fetches repository keys.
- CVE-2026-42574High
Vulnerability in apko (versions 0.14.8 through before 1.2.5) allows a crafted .apk to install a TypeSymlink tar entry pointing outside the build root. Subsequent entries in the archive can traverse that symlink to reach host paths the build user can write to.
Original NVD description (English source)
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.