{
  "cveId": "CVE-2026-64655",
  "url": "https://patchblox.com/security/cve/CVE-2026-64655",
  "summary": "CVE-2026-64655 is fixed in 2 products on 2 platforms, first by GitHub CLI 2.97.0, released July 31, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "GitHub CLI: Attestation Verification Bypass via Unescaped Regex Metacharacters in SAN Matching",
  "description": "GitHub CLI (gh) is GitHub\u2019s 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\u0060.\u0060\u00A0 in organization, repository, and workflow path names and \u00A0\u0060.\u0060\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.",
  "published": "2026-08-06T22:18:13Z",
  "severity": "Low",
  "cvss": 2.1,
  "cwe": "Incorrect Regular Expression",
  "epss": 0.00343,
  "epssPercentile": 0.28046,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64655",
  "fixes": [
    {
      "platform": "windows-app",
      "product": "GitHub CLI",
      "fixedVersion": "2.97.0",
      "fix": "GitHub CLI 2.97.0",
      "url": "https://patchblox.com/security/fix/windows-app/github.cli-2.97.0",
      "released": "2026-07-31T00:00:00Z"
    },
    {
      "platform": "linux",
      "product": "gh",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "2.98.0-bp160.1.1",
      "fix": "OPENSUSE-SU-2026:21663-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21663-1",
      "released": "2026-08-26T16:15:07Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}