CVE-2026-42576: chainguard-dev apko · Incorrect Type Conversion or Cast
Affects chainguard-dev apkoSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium : upgrade to 1.2.7 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 16% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 1.2.7
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade apko and chainguard-dev/apko to 1.2.7.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| chainguard-devapko | Affected
| Fixed in
|
GitHubchainguard-dev/apkopkg:github/chainguard-dev/apkoOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability is available in apko version 1.2.7. Users should upgrade to version 1.2.7 or later to prevent crashes caused by non-RSA JWKS keys. No other mitigations are indicated or required.
Description
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.