Is CVE-2026-64655 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-64655 being exploited in the wild.

How severe is CVE-2026-64655?

Medium severity, with a CVSS score of 4, published 6 August 2026.

Which products and versions are affected?

github.com/cli/cli (Go) SEMVER:introduced=0; github.com/cli/cli/v2 (Go) < 2.97.0, SEMVER:introduced=0,fixed=2.97.0.

Is there a fix for CVE-2026-64655?

Yes. github.com/cli/cli/v2 (Go): upgrade to 2.97.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-64655 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-64655?

Check whether you run github.com/cli/cli (Go) or github.com/cli/cli/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-64655: GitHub CLI attestation verification regex bypass

Q: Is there a fix for CVE-2026-64655?

Yes. github.com/cli/cli/v2 (Go): upgrade to 2.97.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-64655 attacked?

It is attacked over the network, in a web application.

Q: Am I affected by CVE-2026-64655?

Check whether you run github.com/cli/cli (Go) or github.com/cli/cli/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-64655 · Severity: medium · CVSS 4 · Published 2026-08-06

GitHub CLI is the official command-line tool for interacting with GitHub. The `gh attestation verify` command failed to properly escape regex metacharacters when validating Sigstore attestations against trusted signing workflows, allowing an attacker to register a lookalike repository (e.g., `github/artifact.attestations-workflows` instead of `github/artifact-attestations-workflows`) that would pass verification. This could let an attacker inject malicious code into CI/CD pipelines or bypass supply chain security policies that rely on attestation verification.

Technologies: github.com/cli/cli (Go), github.com/cli/cli/v2 (Go). Vendors: Go.

Quick answers

Is CVE-2026-64655 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-64655 being exploited in the wild.
How severe is CVE-2026-64655?: Medium severity, with a CVSS score of 4, published 6 August 2026.
Which products and versions are affected?: github.com/cli/cli (Go) SEMVER:introduced=0; github.com/cli/cli/v2 (Go) < 2.97.0, SEMVER:introduced=0,fixed=2.97.0.
Is there a fix for CVE-2026-64655?: Yes. github.com/cli/cli/v2 (Go): upgrade to 2.97.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-64655 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-64655?: Check whether you run github.com/cli/cli (Go) or github.com/cli/cli/v2 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

github.com/cli/cli/v2 (Go): upgrade to 2.97.0 or later
```
go get github.com/cli/cli/v2@v2.97.0
```

Technical details

The vulnerability is a regex injection flaw in the `gh attestation verify` command. When the `--signer-repo` and `--signer-workflow` flags are used to specify a trusted signer, the tool constructs a certificate Subject Alternative Name matcher without escaping regex metacharacters. Characters like `.` that are valid in GitHub organization, repository, and workflow names are regex wildcards, allowing an attacker to craft a repository name that matches a different intended signer. Exploitation requires creating a plausible lookalike repository and generating valid Sigstore attestations from it. The attack vector is network-based, requiring no authentication or special user interaction beyond the user running the verify command. The fix was applied in version 2.97.0 by properly escaping the metacharacters.

Affected products

GitHub CLI before 2.97.0

Identifiers

CVE-2026-64655
GHSA-mm27-mwq9-fr5g
GO-2026-6767

Timeline

2026-08-06: disclosed
2026-07-31: patched: Fixed in version 2.97.0

References

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