CVE-2026-42576
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk17th percentile - higher than 17% of all known CVEs
Summary
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.
Risk Assessment
An attacker can crash apko, disrupting container image builds and potentially causing denial of service (DoS) in CI/CD environments.
Recommendation
Update apko to version 1.2.7 or later, which includes a fix that checks the key type before assertion.
Other vulnerabilities in apko
See all- CVE-2026-42575High
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.
- 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, DiscoverKeys 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. This issue has been patched in version 1.2.7.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS