{"cve":"CVE-2026-64655","nvd":{"published":"2026-08-06T22:18:13.527","modified":"2026-09-10T20:36:14.340","status":"Awaiting Analysis","description":"GitHub CLI (gh) is GitHub’s official command line tool. Prior to 2.97.0, gh attestation verify  builds the certificate Subject Alternative Name matcher from the --signer-repo and --signer-workflow  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  `.`  in organization, repository, and workflow path names and  `.`  is a regex wildcard, an attacker can register a lookalike name (for example github/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.","cvss_v4":{"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},"cvss_v3":null,"cwes":["CWE-185"],"references":["https://github.com/cli/cli/commit/55dbb4dc6b7edb10b48e3d7fc5bccd32318d1b55","https://github.com/cli/cli/releases/tag/v2.97.0","https://github.com/cli/cli/security/advisories/GHSA-mm27-mwq9-fr5g"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:47:10.050265369+00:00"},"epss":{"cve":"CVE-2026-64655","score":0.00343,"percentile":0.27902,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-mm27-mwq9-fr5g","url":"https://osv.dev/vulnerability/GHSA-mm27-mwq9-fr5g","summary":"GitHub CLI allows attestation verification bypass through unescaped regex metacharacters","modified":"2026-10-19T21:41:04.715150068Z","packages":[{"ecosystem":"Go","name":"github.com/cli/cli/v2","purl":"pkg:golang/github.com/cli/cli/v2","ranges":["<2.97.0"],"fixed":["2.97.0"]}]},{"id":"GO-2026-6767","url":"https://osv.dev/vulnerability/GO-2026-6767","summary":"GitHub CLI allows attestation verification bypass through unescaped regex metacharacters in github.com/cli/cli","modified":"2026-10-19T21:31:49.979387869Z","packages":[{"ecosystem":"Go","name":"github.com/cli/cli","purl":"pkg:golang/github.com/cli/cli","ranges":["all versions"],"fixed":[]},{"ecosystem":"Go","name":"github.com/cli/cli/v2","purl":"pkg:golang/github.com/cli/cli/v2","ranges":["<2.97.0"],"fixed":["2.97.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}