CVE-2026-42575

HIGH 7.5

apko doesn't verify downloaded apk packages against APKINDEX checksum (package substitution possible)

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

3th

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.

CWE	CWE-345 CWE-494
Vendor	chainguard-dev
Product	apko
Published	May 9, 2026
Last Updated	May 13, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Affected Versions

chainguard-dev / apko

< 1.2.7

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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