CVE-2026-31830 HIGH

CVE-2026-31830: sigstore-ruby verifier returns success for DSSE bundles with mismatched in-toto subject digest

Vendor Sigstore
Product sigstore-ruby
Weakness CWE-252
Published March 10, 2026
Last update March 11, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity High

CVSS vector

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

What the vulnerability does

01Description

sigstore-ruby is a pure Ruby implementation of the sigstore verify command from the sigstore/cosign project. Prior to 0.2.3, Sigstore::Verifier#verify does not propagate the VerificationFailure returned by verify_in_toto when the artifact digest does not match the digest in the in-toto attestation subject. As a result, verification of DSSE bundles containing in-toto statements returns VerificationSuccess regardless of whether the artifact matches the attested subject. This vulnerability is fixed in 0.2.3.

Key dates

02Disclosure timeline

March 10, 2026 CVE published
March 11, 2026 Record updated