PT-2026-31010 · Sigstore · Cosign

Published 2026-04-07 · Updated 2026-04-07 · CVE-2026-39395

Mitre

CVSS v3.1

4.3

Medium

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

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.

Fix

Improper Check for Exceptional Conditions

Weakness Enumeration

CWE-754

Related Identifiers

CVE-2026-39395

Affected Products

Cosign

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-39395 · Security Note
• https://github.com/sigstore/cosign/security/advisories/GHSA-w6c6-c85g-mmv6 · Note