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 metacha…
Exact source revision recorded 5 Nov 2026 12:48:43 UTC. It does not establish the source's current position. Latest evidence.
euvd · EUVD-2026-54222
PublishedGitHub 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.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Aug 6, 2026, 6:41:54 PM
dateUpdated: Aug 8, 2026, 2:23:17 AM
3 related source bulletins · separate from aliases
msrc_CVE-2026-64655: GitHub CLI: Attestation Verification Bypass via Unescaped Regex Metacharacters in SAN Matching
CVE-2026-64655
openSUSE-SU-2026:21663-1: Security update for gh
CVE-2026-39821 · CVE-2026-64652 · CVE-2026-64653 · CVE-2026-64654 · CVE-2026-64655
openSUSE-SU-2026:11530-1: gh-2.97.0-1.1 on GA media
CVE-2026-64652 · CVE-2026-64653 · CVE-2026-64654 · CVE-2026-64655
- Source published
- Aug 6, 2026, 6:41:54 PM (timezone not stated)
- Source modified
- Aug 8, 2026, 2:23:17 AM (timezone not stated)
- Observed here
- 5 Nov 2026 12:48:43 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.
EUVD CVSS 4.0 · 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