What is CVE-2026-42576?

CVE-2026-42576 is a medium-severity vulnerability in Chainguard-Dev Apko, classified under Incorrect Type Conversion or Cast. CVSS score: 6.5/10. Published 2026-05-09.

How severe is CVE-2026-42576?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Chainguard-Dev Apko

CVE-2026-42576

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.

EPSS: 0.003 (16.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Chainguard-dev Apko — versions < 1.2.7

Weakness classification (CWE)

CWE-704 — Incorrect Type Conversion or Cast

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-2026-42576?: CVE-2026-42576 is a medium-severity vulnerability in Chainguard-Dev Apko, classified under Incorrect Type Conversion or Cast. CVSS score: 6.5/10. Published 2026-05-09.
How severe is CVE-2026-42576?: Medium severity. CVSS v3 base score is 6.5 out of 10.