Skip to content

apko `DiscoverKeys` has a panic on non-rsa jwks key that causes crash during key discovery

Moderate severity GitHub Reviewed Published Apr 23, 2026 in chainguard-dev/apko • Updated May 13, 2026

Package

gomod chainguard.dev/apko (Go)

Affected versions

< 1.2.7

Patched versions

1.2.7

Description

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. Affected versions <= 0.30.34.

Fix: No fix available yet.

Acknowledgements

apko thanks Oleh Konko from 1seal for discovering and reporting this issue.

References

@antitree antitree published to chainguard-dev/apko Apr 23, 2026
Published to the GitHub Advisory Database May 4, 2026
Reviewed May 4, 2026
Published by the National Vulnerability Database May 9, 2026
Last updated May 13, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(12th percentile)

Weaknesses

Incorrect Type Conversion or Cast

The product does not correctly convert an object, resource, or structure from one type to a different type. Learn more on MITRE.

CVE ID

CVE-2026-42576

GHSA ID

GHSA-m7hm-vm4x-28jf

Source code

Credits

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.
⚡