CVE-2026-39395

MEDIUM

4.3

Description

Cosign provides code signing and transparency for containers and binaries. Prior to 3.0.6 and 2.6.3, cosign verify-blob-attestation may erroneously report a "Verified OK" result for attestations with malformed payloads or mismatched predicate types. For old-format bundles and detached signatures, this was due to a logic flaw in the error handling of the predicate type validation. For new-format bundles, the predicate type validation was bypassed completely. This vulnerability is fixed in 3.0.6 and 2.6.3.

CVE Details

CVSS v3.1 Score4.3

SeverityMEDIUM

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

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionREQUIRED

Published4/7/2026

Last Modified4/15/2026

Sourcenvd

Honeypot Sightings0

Affected Products

sigstore:cosign

Weaknesses (CWE)

CWE-754

References

https://github.com/sigstore/cosign/security/advisories/GHSA-w6c6-c85g-mmv6(security-advisories@github.com)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.