# CVE-2026-64655

## Summary

- **CVE ID:** CVE-2026-64655
- **Severity:** LOW
- **CVSS Score:** 2.1 (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)
- **CWE:** CWE-185
- **Published:** Aug 6, 2026
- **Last Modified:** Aug 8, 2026

## 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.

## Affected Products

- cli — cli (< 2.97.0)

## References

- [CNA](https://github.com/cli/cli/security/advisories/GHSA-mm27-mwq9-fr5g)
- [CNA](https://github.com/cli/cli/commit/55dbb4dc6b7edb10b48e3d7fc5bccd32318d1b55)
- [CNA](https://github.com/cli/cli/releases/tag/v2.97.0)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.33%
- **EPSS Percentile:** 26.2

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._