Vulnerability · Published Mar 10, 2026 · Assigned by GitHub_M

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

High 7.5

In plain English

A high-severity security flaw in sigstore-ruby from sigstore. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.3%top 79.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
RubyGems	sigstore	0.2.3	GHSA-mhg6-2q2v-9h2c

Affected products (as reported)

Vendor	Product	Versions
sigstore	sigstore-ruby	< 0.2.3

Weakness: CWE-252 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

https://github.com/sigstore/sigstore-ruby/security/advisories/GHSA-mhg6-2q2v-9h2c x_refsource_CONFIRM