{"id":"CVE-2026-64655","revision":"a5a56996f242475fba045507fed53af9","records":[{"revision":"a5a56996f242475fba045507fed53af9","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64655","aliases":[],"title":"GitHub CLI: Attestation Verification Bypass via Unescaped Regex Metacharacters in SAN Matching","description":"GitHub CLI (gh) is GitHub’s official command line tool. Prior to 2.97.0, gh attestation verify\u00A0 builds the certificate Subject Alternative Name matcher from the --signer-repo and --signer-workflow\u00A0 flag values without escaping regex metacharacters, so a user-supplied repository or workflow name is treated as a regular expression rather than a literal string. Because GitHub permits characters such as \u00A0`.`\u00A0 in organization, repository, and workflow path names and \u00A0`.`\u00A0 is a regex wildcard, an attacker can register a lookalike name (for example\u00A0github/artifact.attestations-workflows) that satisfies a matcher intended for a different trusted signer (github/artifact-attestations-workflows), bypassing the intended Sigstore attestation verification. Exploitation requires the attacker to create a plausible lookalike repository and produce valid attestations from it, which could undermine supply chain verification for CI/CD pipelines or policy gates that pin trust to a specific signing workflow. This issue is fixed in version 2.97.0.","state":0,"publishedAt":"2026-08-06T18:41:54.628+00:00","modifiedAt":"2026-08-08T02:23:17.134+00:00","affected":[{"ecosystem":"Vendor product","name":"cli","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"cli\",\n                    \"product\": \"cli\",\n                    \"versions\": [\n                        {\n                            \"version\": \"< 2.97.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N","score":2.1,"severity":"LOW"}],"references":["https://github.com/cli/cli/security/advisories/GHSA-mm27-mwq9-fr5g","https://github.com/cli/cli/commit/55dbb4dc6b7edb10b48e3d7fc5bccd32318d1b55","https://github.com/cli/cli/releases/tag/v2.97.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64655","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64655","identifiers":["CVE-2026-64655"]},"retained":false,"historicalAffected":[]}],"coverage":[]}