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

March 11, 2026 (updated March 19, 2026)

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.

References

github.com/advisories/GHSA-mhg6-2q2v-9h2c
github.com/rubysec/ruby-advisory-db/blob/master/gems/sigstore/CVE-2026-31830.yml
github.com/sigstore/sigstore-ruby
github.com/sigstore/sigstore-ruby/security/advisories/GHSA-mhg6-2q2v-9h2c
nvd.nist.gov/vuln/detail/CVE-2026-31830

Code Behaviors & Features

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