GHSA-fp37-c92q-4pwq is a high-severity (CVSS 8.1) Improper Input Validation vulnerability in k8s.io/apiextensions-apiserver. A fix is available for k8s.io/apiextensions-apiserver — see the affected versions and patch details below.
Kubernetes kube-apiserver unauthorized access
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.
How urgent is this, really
GHSA-fp37-c92q-4pwq plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
k8s.io/apiextensions-apiserver🐹k8s.io/apiextensions-apiserver🐹k8s.io/apiextensions-apiserverReal-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
The Kubernetes kube-apiserver mistakenly allows access to a cluster-scoped custom resource if the request is made as if the resource were namespaced. Authorizations for the resource accessed in this manner are enforced using roles and role bindings within the namespace, meaning that a user with access only to a resource in one namespace could create, view update or delete the cluster-scoped resource (according to their namespace role privileges). Kubernetes affected versions include versions prior to 1.13.9, versions prior to 1.14.5, versions prior to 1.15.2, and versions 1.7, 1.8, 1.9, 1.10, 1.11, 1.12.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | k8s.io/apiextensions-apiserver | ≥ 0.7.0&&< 0.13.9 | 0.13.9go get k8s.io/apiextensions-apiserver@v0.13.9 |
| 🐹Go | k8s.io/apiextensions-apiserver | ≥ 0.14.0&&< 0.14.5 | 0.14.5go get k8s.io/apiextensions-apiserver@v0.14.5 |
| 🐹Go | k8s.io/apiextensions-apiserver | ≥ 0.15.0&&< 0.15.2 | 0.15.2go get k8s.io/apiextensions-apiserver@v0.15.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for k8s.io/apiextensions-apiserver, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update k8s.io/apiextensions-apiserver to 0.13.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fp37-c92q-4pwq 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-fp37-c92q-4pwq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-fp37-c92q-4pwq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift Container Platform 3.10 | atomic-openshift-0:3.10.170-1.git.0.8e592d6.el7 | RHSA-2019:2690 |
| Red Hat OpenShift Container Platform 3.11 | ansible-service-broker-1:1.3.23-2.el7 | RHBA-2019:2816 |
| Red Hat OpenShift Container Platform 3.9 | ansible-service-broker-0:1.1.20-2.el7 | RHSA-2019:2769 |
| Red Hat OpenShift Container Platform 4.1 | openshift-0:4.1.10-201908060758.git.0.d81afa6.el7 | RHSA-2019:2504 |
Frequently Asked Questions
Is GHSA-fp37-c92q-4pwq in your dependencies?
O3 Security finds GHSA-fp37-c92q-4pwq across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.