GitHub CLI up to 2.96.x Attestation Verify signer-repo/signer-workflow incorrect regex

Summaryinfo

A vulnerability classified as problematic was found in GitHub CLI up to 2.96.x. The affected element is an unknown function of the component Attestation Verify. Such manipulation of the argument signer-repo/signer-workflow leads to incorrect regex. This vulnerability is documented as CVE-2026-64655. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in GitHub CLI up to 2.96.x. Affected by this issue is an unknown function of the component Attestation Verify. The manipulation of the argument signer-repo/signer-workflow with an unknown input leads to a incorrect regex vulnerability. Using CWE to declare the problem leads to CWE-185. The product specifies a regular expression in a way that causes data to be improperly matched or compared. Impacted is integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2026-64655 since 07/20/2026. The exploitation is known to be easy. The attack may be launched remotely. There are known technical details, but no exploit is available.

Upgrading to version 2.97.0 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Bug Tracking Software

Vendor

• GitHub

Name

• CLI

Version

• 2.0
• 2.1
• 2.2
• 2.3
• 2.4
• 2.5
• 2.6
• 2.7
• 2.8
• 2.9
• 2.10
• 2.11
• 2.12
• 2.13
• 2.14
• 2.15
• 2.16
• 2.17
• 2.18
• 2.19
• 2.20
• 2.21
• 2.22
• 2.23
• 2.24
• 2.25
• 2.26
• 2.27
• 2.28
• 2.29
• 2.30
• 2.31
• 2.32
• 2.33
• 2.34
• 2.35
• 2.36
• 2.37
• 2.38
• 2.39
• 2.40
• 2.41
• 2.42
• 2.43
• 2.44
• 2.45
• 2.46
• 2.47
• 2.48
• 2.49
• 2.50
• 2.51
• 2.52
• 2.53
• 2.54
• 2.55
• 2.56
• 2.57
• 2.58
• 2.59
• 2.60
• 2.61
• 2.62
• 2.63
• 2.64
• 2.65
• 2.66
• 2.67
• 2.68
• 2.69
• 2.70
• 2.71
• 2.72
• 2.73
• 2.74
• 2.75
• 2.76
• 2.77
• 2.78
• 2.79
• 2.80
• 2.81
• 2.82
• 2.83
• 2.84
• 2.85
• 2.86
• 2.87
• 2.88
• 2.89
• 2.90
• 2.91
• 2.92
• 2.93
• 2.94
• 2.95
• 2.96

License

• open-source

CPE 2.3info

• 🔒
• 🔒
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CPE 2.2info

• 🔒
• 🔒
• 🔒

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