`gh attestation verify` returns incorrect exit code during verification if no attestations are presentGHSA-fgw4-v983-mgp8
MEDIUMFix: cli/cli#10421GHSA-fgw4-v983-mgp8 is a medium-severity (CVSS 6.3) CWE-390 vulnerability in github.com/cli/cli/v2. A fix is available for github.com/cli/cli/v2 — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-fgw4-v983-mgp8.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/cli/cli/v2Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A bug in GitHub's Artifact Attestation CLI tool, gh attestation verify, may return an incorrect zero exit status when no matching attestations are found for the specified --predicate-type <value> or the default https://slsa.dev/provenance/v1 if not specified. This issue only arises if an artifact has an attestation with a predicate type different from the one provided in the command. As a result, users relying solely on these exit codes may mistakenly believe the attestation has been verified, despite the absence of an attestation with the specified predicate type and the tool printing a verification failure.
Users are advised to update gh to version v2.67.0 as soon as possible.
Initial report: https://github.com/cli/cli/issues/10418 Fix: https://github.com/cli/cli/pull/10421
Details
The gh attestation verify command fetches, loads, and attempts to verify attestations associated with a given artifact for a specified predicate type. If an attestation is found, but the predicate type does not match the one specified in the gh attestation verify command, the verification fails, but the program exits early.
Due to a re-used uninitialized error variable, when no matching attestations are found, the relevant function returns nil instead of an error, causing the program to exit with a status code of 0, which incorrectly suggests successful verification.
PoC
Run gh attestation verify with local attestations using the --bundle flag and specify a predicate type with --predicate-type that you know will not match any of the attestations the command will attempt to verify. Confirm that the command exits with a zero status code.
Impact
Users who rely exclusively on the exit status code of gh attestation verify may incorrectly verify an attestation when the attestation's predicate type does not match the specified predicate type in the command.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cli/cli/v2 | ≥ 2.49.0&&< 2.67.0 | 2.67.0go get github.com/cli/cli/v2@v2.67.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cli/cli/v2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/cli/cli/v2 to 2.67.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fgw4-v983-mgp8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is GHSA-fgw4-v983-mgp8 in your dependencies?
Find it across Go, including transitive dependencies.