{"id":"EUVD-2026-54222","revision":null,"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":[]},{"revision":"6dc5af6cdf7b4312a1cd04eaaea56f85","observedAt":"2026-11-07T13:31:07.902+00:00","statement":{"source":"euvd","id":"EUVD-2026-54222","aliases":["CVE-2026-64655","GHSA-mm27-mwq9-fr5g"],"title":"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 metacha…","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":null,"modifiedAt":null,"affected":[],"metrics":[{"system":"EUVD 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":null}],"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://euvd.enisa.europa.eu/vulnerability/EUVD-2026-54222","license":"ENISA EUVD · source terms and attribution apply","enrichment":{"sourceStatus":null,"weaknesses":[],"productCriteria":[],"sourceDates":{"datePublished":"Aug 6, 2026, 6:41:54 PM","dateUpdated":"Aug 8, 2026, 2:23:17 AM"},"relatedAdvisories":[{"id":"msrc_CVE-2026-64655","title":"GitHub CLI: Attestation Verification Bypass via Unescaped Regex Metacharacters in SAN Matching","vulnerabilityIds":["CVE-2026-64655"]},{"id":"openSUSE-SU-2026:21663-1","title":"Security update for gh","vulnerabilityIds":["CVE-2026-39821","CVE-2026-64652","CVE-2026-64653","CVE-2026-64654","CVE-2026-64655"]},{"id":"openSUSE-SU-2026:11530-1","title":"gh-2.97.0-1.1 on GA media","vulnerabilityIds":["CVE-2026-64652","CVE-2026-64653","CVE-2026-64654","CVE-2026-64655"]}],"note":"EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON."},"key":"euvd:EUVD-2026-54222","identifiers":["EUVD-2026-54222","CVE-2026-64655","GHSA-mm27-mwq9-fr5g"]},"retained":false,"historicalAffected":[]},{"revision":"f4a3643b9a0148f6ad5cd9a2e1ba9fa6","observedAt":"2026-10-25T15:18:45.851+00:00","statement":{"source":"nvd","id":"CVE-2026-64655","aliases":[],"title":"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 metacha…","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":"2026-08-06T22:18:13.527+00:00","modifiedAt":"2026-09-10T20:36:14.34+00:00","affected":[],"metrics":[{"system":"CVSS 4.0 · security-advisories@github.com · Secondary","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","score":2.1,"severity":"LOW"}],"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"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64655","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Awaiting Analysis","weaknesses":["CWE-185"],"productCriteria":[],"sourceDates":{"published":"2026-08-06T22:18:13.527","lastModified":"2026-09-10T20:36:14.340"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-64655","identifiers":["CVE-2026-64655"]},"retained":false,"historicalAffected":[]},{"revision":"a19adcb8bfd2435fa172e67ed84ae894","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-mm27-mwq9-fr5g","aliases":["CVE-2026-64655","GO-2026-6767"],"title":"GitHub CLI allows attestation verification bypass through unescaped regex metacharacters","description":"### Summary\n\nA security vulnerability has been identified in GitHub CLI that could allow attestation verification bypass when using `gh attestation verify` with `--signer-repo` or `--signer-workflow` flags. GitHub CLI builds the certificate matcher from these flag values without escaping regex metacharacters, so a repository or workflow name is treated as a regular expression rather than a literal string. GitHub permits characters such as \u00A0`.`\u00A0 in organization, repository, and workflow path names, and \u00A0`.`\u00A0 is a regex wildcard, so a malicious actor can create a lookalike name that satisfies a matcher intended for a different, trusted signer.\n\n### Details\n\nGitHub CLI constructs a regular expression from the \u00A0`--signer-repo`\u00A0 and \u00A0`--signer-workflow`\u00A0 values and matches it against the signing certificate's SAN (Subject Alternative Name) during Sigstore attestation verification. The user-supplied value is interpolated into the pattern without escaping regex metacharacters, so any metacharacter permitted in a GitHub path is interpreted as regex syntax instead of a literal character.\n\nThe most practical case is \u00A0`.`\u00A0, which GitHub allows in org/repo names and is a regex wildcard meaning \"any single character.\" For example, an attacker-controlled repository named:\n\n`github/artifact.attestations-workflows`\n\nmatches a verifier configured for the trusted signer:\n\n`github/artifact-attestations-workflows`\n\nbecause the unescaped \u00A0`.`\u00A0 in the constructed pattern matches the \u00A0`-`\u00A0 in the attacker's name (and any other single character at that position). This affected the `--signer-repo` and `--signer-workflow` flags but did not affect the `--repo` and `--owner` flags which include an exact string comparison.\n\nIn `v2.97.0`, the GitHub CLI escapes the user-supplied signer values before they are incorporated into the SAN matcher, so they are matched as literal strings.\n\n### Impact\n\nThe practical impact is limited, exploitation requires the attacker to create a plausible lookalike repository name and produce valid Sigstore attestations from it. This could undermine supply chain verification for CI/CD pipelines or policy gates that use these flags to pin trust to a specific signing workflow. \n\n### Remediation and Mitigation\n\n1. Upgrade `gh` to `v2.97.0` or later, which escapes signer values before matching.\n2. As a workaround, use `--repo` or `--owner` flags instead of `--signer-repo` or `--signer-workflow` where applicable.\n3. Manually inspect the signing certificate SAN in attestation output to confirm the signing workflow origin.","state":0,"publishedAt":"2026-10-15T18:08:20+00:00","modifiedAt":"2026-10-19T21:41:04.7151501+00:00","affected":[{"ecosystem":"Go","name":"github.com/cli/cli/v2","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"2.97.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"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":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"LOW"}],"references":["https://github.com/cli/cli/security/advisories/GHSA-mm27-mwq9-fr5g","https://nvd.nist.gov/vuln/detail/CVE-2026-64655","https://github.com/cli/cli/commit/55dbb4dc6b7edb10b48e3d7fc5bccd32318d1b55","https://github.com/cli/cli","https://github.com/cli/cli/releases/tag/v2.97.0"],"sourceUrl":"https://github.com/advisories/GHSA-mm27-mwq9-fr5g","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-mm27-mwq9-fr5g","identifiers":["GHSA-mm27-mwq9-fr5g","CVE-2026-64655","GO-2026-6767"]},"retained":false,"historicalAffected":[]},{"revision":"1d7712998bea4349bc0e2cb1e19bc56c","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GO-2026-6767","aliases":["CVE-2026-64655","GHSA-mm27-mwq9-fr5g"],"title":"GitHub CLI allows attestation verification bypass through unescaped regex metacharacters in github.com/cli/cli","description":"GitHub CLI allows attestation verification bypass through unescaped regex metacharacters in github.com/cli/cli","state":0,"publishedAt":"2026-10-19T21:08:35+00:00","modifiedAt":"2026-10-19T21:31:49.9793879+00:00","affected":[{"ecosystem":"Go","name":"github.com/cli/cli","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"Go","name":"github.com/cli/cli/v2","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"2.97.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[],"references":["https://github.com/cli/cli/security/advisories/GHSA-mm27-mwq9-fr5g","https://nvd.nist.gov/vuln/detail/CVE-2026-64655","https://github.com/cli/cli/commit/55dbb4dc6b7edb10b48e3d7fc5bccd32318d1b55","https://github.com/cli/cli/releases/tag/v2.97.0"],"sourceUrl":"https://osv.dev/vulnerability/GO-2026-6767","license":"OSV · upstream source license applies","key":"osv:GO-2026-6767","identifiers":["GO-2026-6767","CVE-2026-64655","GHSA-mm27-mwq9-fr5g"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-383c643166b94ac4b6a615647191978e","complete":true,"records":13654,"lastAttemptAt":"2026-11-08T14:04:47.6384375+00:00","lastSuccessAt":"2026-11-08T13:04:50.073+00:00","error":null,"lastVerifiedAt":"2026-11-08T13:04:50.073+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. 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