CVE-2023-3955 — kubernetes
HIGHCVE-2023-3955 is a high-severity (CVSS 8.8) Improper Input Validation vulnerability in k8s.io/kubernetes. 1 public exploit reference exists, so weaponization risk is real. A fix is available for k8s.io/kubernetes — see the affected versions and patch details below.
Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-3955.
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
CVE-2023-3955 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 377,166 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/kubernetes🐹k8s.io/kubernetes🐹k8s.io/kubernetes🐹k8s.io/kubernetes🐹k8s.io/kubernetesReal-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
A security issue was discovered in Kubernetes where a user that can create pods on Windows nodes may be able to escalate to admin privileges on those nodes. Kubernetes clusters are only affected if they include Windows nodes.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | k8s.io/kubernetes | ≥ 1.28.0&&< 1.28.1 | 1.28.1go get k8s.io/kubernetes@v1.28.1 |
| 🐹Go | k8s.io/kubernetes | ≥ 1.27.0&&< 1.27.5 | 1.27.5go get k8s.io/kubernetes@v1.27.5 |
| 🐹Go | k8s.io/kubernetes | ≥ 1.26.0&&< 1.26.8 | 1.26.8go get k8s.io/kubernetes@v1.26.8 |
| 🐹Go | k8s.io/kubernetes | ≥ 1.25.0&&< 1.25.13 | 1.25.13go get k8s.io/kubernetes@v1.25.13 |
| 🐹Go | k8s.io/kubernetes | all versions | 1.24.17go get k8s.io/kubernetes@v1.24.17 |
Research 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 k8s.io/kubernetes, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update k8s.io/kubernetes to 1.28.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-3955 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 CVE-2023-3955 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-3955. 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.
Kubernetes clusters are only affected if they include Windows nodes. Any Kubernetes environment with Windows nodes is impacted. Run kubectl get nodes -l kubernetes.io/os=windows to see if any Windows nodes are in use.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift Container Platform 4.10 | openshift4-wincw/windows-machine-config-rhel8-operator:5.1.2-3 | RHSA-2023:4835 |
| Red Hat OpenShift Container Platform 4.11 | openshift4-wincw/windows-machine-config-rhel8-operator:6.0.2-5 | RHSA-2023:4780 |
| Red Hat OpenShift Container Platform 4.12 | openshift4-wincw/windows-machine-config-rhel8-operator:7.1.1-9 | RHSA-2023:4777 |
| Red Hat OpenShift Container Platform 4.13 | openshift4-wincw/windows-machine-config-rhel9-operator:8.0.2-9 | RHSA-2023:4885 |
| Red Hat OpenShift Container Platform 4.14 | openshift4-wincw/windows-machine-config-operator-bundle:v9.0.0-104 | RHSA-2023:7515 |
Frequently Asked Questions
Is CVE-2023-3955 in your dependencies?
O3 Security finds CVE-2023-3955 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.