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

{
  "id": "9aa559cdc9aa8be1de07117d748912ba4070f99353a604f7af4d3cc4cb81e597",
  "url": "https://osv.dev/vulnerability/CVE-2026-31830",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "sigstore-ruby verifier returns success for DSSE bundles with mismatched in-toto subject digest",
    "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.",
    "evidence": "osv:CVE-2026-31830",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-31830",
      "aliases": [
        "CVE-2026-31830",
        "GHSA-mhg6-2q2v-9h2c"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/sigstore/sigstore-ruby",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "26ffbe0c1d6e16614fb9cd8b2ed40ab47d57d421"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.2.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:sigstore:sigstore:*:*:*:*:*:ruby:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.2.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.2.2",
            "v0.2.1",
            "v0.2.0",
            "v0.1.1",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-31830.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.539384313Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31830.json",
        "https://github.com/sigstore/sigstore-ruby/security/advisories/GHSA-mhg6-2q2v-9h2c",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-31830"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-252"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31830.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-31830",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490171,
  "published_at": "2026-03-10T21:46:02.547+00:00"
}