---
id: CVE-2026-64655
title: GitHub CLI (gh) is GitHub’s official command line tool
summary: "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 meta…"
severity: none
cwe:
  - CWE-185
published: '2026-08-06'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T20:36:14.340'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64655'
references:
  - url: 'https://github.com/cli/cli/commit/55dbb4dc6b7edb10b48e3d7fc5bccd32318d1b55'
    label: security-advisories@github.com
  - url: 'https://github.com/cli/cli/releases/tag/v2.97.0'
    label: security-advisories@github.com
  - url: 'https://github.com/cli/cli/security/advisories/GHSA-mm27-mwq9-fr5g'
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00333
epssPercentile: 0.26708
ingestedAt: '2026-08-09T00:31:25.091Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.