CVE-2026-64655

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

No CVSS.

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-06 22:18

Updated : 2026-09-10 20:36

NVD link : CVE-2026-64655

Mitre link : CVE-2026-64655

CVE.ORG link : CVE-2026-64655

JSON object : View

Products Affected

No product.

CWE

CWE-185

Incorrect Regular Expression

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