TI-2026-24383 Aliases CVE-2026-31830 GHSA-mhg6-2q2v-9h2c

sigstore-ruby verifier returns success for DSSE bundles with mismatched in-toto subject digest

LOW 39CWE-252Published 2026-03-10 · Updated 2026-03-11

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: None · High · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00278 20th percentileScored 2026-11-07

Fix Fixed sigstore-ruby (sigstore): 0.2.3sigstore (RubyGems): 0.2.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
sigstore	sigstore-ruby	before 0.2.3	0.2.3	Patch available	CNA
—	sigstore (RubyGems)	before 0.2.3	0.2.3	Patch available	GHSA-mhg6-2q2v-9h2c

sigstore-ruby Vendorsigstore Affected before 0.2.3 Fixed in 0.2.3 Patch available CNA
sigstore (RubyGems) Vendor— Affected before 0.2.3 Fixed in 0.2.3 Patch available GHSA-mhg6-2q2v-9h2c

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:sigstore:sigstore::::::ruby::*	before 0.2.3	Vulnerable	sigstore

cpe:2.3:a:sigstore:sigstore:*:*:*:*:*:ruby:*:* Versions before 0.2.3 Vulnerable ·sigstore

Remediation

Fix · CNA sigstore-ruby (sigstore) Fixed in 0.2.3
Fix · GHSA-mhg6-2q2v-9h2c sigstore (RubyGems) Fixed in 0.2.3 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-31830
2026-10-03 Alias added: GHSA-mhg6-2q2v-9h2c

References

Advisory 2

Other 2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences