GHSA-8pmp-678w-c8xx — gitsign
GHSA-8pmp-678w-c8xx is a CWE-706 vulnerability in github.com/sigstore/gitsign. A fix is available for github.com/sigstore/gitsign — see the affected versions and patch details below.
gitsign may use incorrect Rekor entries during verification
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.
Exploitation and automatability from CISA’s SSVC triage for GHSA-8pmp-678w-c8xx.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
github.com/sigstore/gitsignReal-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
gitsign may select the wrong Rekor entry to use during online verification when multiple entries are returned by the log.
Details
gitsign uses Rekor's search API to fetch entries that apply to a signature being verified. The parameters used for the search are the public key and the payload. The search API returns entries that match either condition rather than both. When gitsign's credential cache is used, there can be multiple entries that use the same ephemeral keypair / signing certificate. As gitsign assumes both conditions are matched by Rekor, there is no additional validation that the entry's hash matches the payload being verified, meaning that the wrong entry can be used to successfully pass verification.
PoC
Enable the credential cache and create commit signatures using the cached signing certificate. gitsign verify or git log --show-signature will demonstrate the use of the wrong entry index for the corresponding commit. Note that this depends on the order of matching entries in the response from the Rekor search API, so it may take a few attempts to trigger this.
Impact
Minimal. While gitsign does not match the payload against the entry, it does ensure that the certificate matches. This would need to be exploited during the certificate validity window (10 minutes) by the key holder.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/sigstore/gitsign | all versions | 0.11.0go get github.com/sigstore/gitsign@v0.11.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/sigstore/gitsign, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/sigstore/gitsign to 0.11.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8pmp-678w-c8xx 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-8pmp-678w-c8xx can be triaged on real exposure rather than presence alone.
Tailored to GHSA-8pmp-678w-c8xx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8pmp-678w-c8xx in your dependencies?
O3 Security finds GHSA-8pmp-678w-c8xx across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.