CVE-2026-39395

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.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/sigstore/cosign/security/advisories/GHSA-w6c6-c85g-mmv6	Mitigation Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:sigstore:cosign::::::::
	cpe:2.3:a:sigstore:cosign::::::::

History

No history.

Information

Published : 2026-04-07 20:16

Updated : 2026-07-24 21:10

NVD link : CVE-2026-39395

Mitre link : CVE-2026-39395

CVE.ORG link : CVE-2026-39395

JSON object : View

Products Affected

sigstore

cosign

CWE

CWE-754

Improper Check for Unusual or Exceptional Conditions

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