Answer in brief
CVE-2026-64655 records a Low severity (CVSS 2.1) vulnerability in GitHub CLI: Attestation Verification Bypass via Unescaped Regex Metacharacters in SAN Matching. The current sources do not mark it as known exploited. The current feed maps cli/cli (generic), github.com/cli/cli (go), github.com/cli/cli/v2 (go), github.com/cli/cli/v2 (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 2.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps cli/cli (generic), github.com/cli/cli (go), github.com/cli/cli/v2 (go), github.com/cli/cli/v2 (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| cli/cligeneric | <2.97.0 | 2.97.0 |
| github.com/cli/cligo | >=0 | Not reported |
| github.com/cli/cli/v2go | <2.97.0 | 2.97.0 |
| github.com/cli/cli/v2go | >=0 <2.97.0 | 2.97.0 |
Published upstream
Aug 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 6, 2026
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.
Quoted source text, attributed separately from HOL analysis.