UBUNTU-CVE-2026-64655

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Source
https://ubuntu.com/security/CVE-2026-64655
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-64655.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-64655
Upstream
Published
2026-08-07T00:00:00Z
Modified
2026-08-07T17:45:23.990485233Z
Severity
  • 2.1 (Low) CVSS_V4 - 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 CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:22.04:LTS / gh

Package

Name
gh
Purl
pkg:deb/ubuntu/gh?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.4.0+dfsg1-1
2.4.0+dfsg1-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.4.0+dfsg1-2",
            "binary_name": "gh"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-64655.json"

Ubuntu:Pro:24.04:LTS / gh

Package

Name
gh
Purl
pkg:deb/ubuntu/gh?arch=source&distro=esm-apps%2Fnoble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.27.0+dfsg1-1build1
2.30.0-2
2.35.0-1
2.40.1+dfsg1-1
2.42.1-1
2.43.1-1
2.44.1-1
2.44.1-2
2.45.0-1
2.45.0-1build1
2.45.0-1ubuntu0.1
2.45.0-1ubuntu0.2
2.45.0-1ubuntu0.2+esm1
2.45.0-1ubuntu0.2+esm2
2.45.0-1ubuntu0.3
2.45.0-1ubuntu0.3+esm1
2.45.0-1ubuntu0.3+esm2
2.45.0-1ubuntu0.3+esm3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.45.0-1ubuntu0.3+esm3",
            "binary_name": "gh"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-64655.json"

Ubuntu:Pro:26.04:LTS / gh

Package

Name
gh
Purl
pkg:deb/ubuntu/gh?arch=source&distro=esm-apps%2Fresolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*
2.46.0-3
2.46.0-4
2.46.0-4ubuntu0.26.04.1~esm1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.46.0-4ubuntu0.26.04.1~esm1",
            "binary_name": "gh"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-64655.json"