cosign's `cosign verify-attestaton --type` can report a false positive if any attestation existsGHSA-vjxv-45g9-9296
HIGHFix: sigstore/cosign@c5fda01GHSA-vjxv-45g9-9296 is a high-severity (CVSS 7.1) CWE-347 vulnerability in github.com/sigstore/cosign. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for github.com/sigstore/cosign — 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-vjxv-45g9-9296.
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/sigstore/cosignReal-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
cosign is a container signing and verification utility. In versions prior to 1.10.1 cosign can report a false positive if any attestation exists. cosign verify-attestation used with the --type flag will report a false positive verification when there is at least one attestation with a valid signature and there are NO attestations of the type being verified (--type defaults to "custom"). This can happen when signing with a standard keypair and with "keyless" signing with Fulcio. This vulnerability can be reproduced with the distroless.dev/static@sha256:dd7614b5a12bc4d617b223c588b4e0c833402b8f4991fb5702ea83afad1986e2 image. This image has a vuln attestation but not an spdx attestation. However, if you run cosign verify-attestation --type=spdx on this image, it incorrectly succeeds. This issue has been addressed in version 1.10.1 of cosign. Users are advised to upgrade. There are no known workarounds for this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/sigstore/cosign | all versions | 1.10.1go get github.com/sigstore/cosign@v1.10.1 |
Affected Products
cosignsigstoreResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
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/cosign, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/sigstore/cosign to 1.10.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vjxv-45g9-9296 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-vjxv-45g9-9296 in your dependencies?
Find it across Go, including transitive dependencies.