CVE-2026-29773 is a medium-severity (CVSS 4.3) CWE-863 vulnerability in github.com/kubewarden/kubewarden-controller. A fix is available for github.com/kubewarden/kubewarden-controller — see the affected versions and patch details below.
kubewarden-controller cross-namespace data exfiltration via deprecated host callback binding
Exploitation Status
No confirmed exploitation observed yet
- 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-2026-29773.
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-2026-29773 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 378,156 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
github.com/kubewarden/kubewarden-controllerReal-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
Impact
Kubewarden is a policy engine for Kubernetes. Kubewarden cluster operators can grant permissions to users to deploy namespaced AdmissionPolicies and AdmissionPolicyGroups in their Namespaces. One of Kubewarden promises is that configured users can deploy namespaced policies in a safe manner, without privilege escalation.
An attacker with privileged "AdmissionPolicy" create permissions (which isn't the default) could make use of 3 deprecated host-callback APIs: kubernetes/ingresses, kubernetes/namespaces, kubernetes/services.
The attacker can craft a policy that exercises these deprecated API calls and would allow them read access to Ingresses, Namespaces, and Services resources respectively.
This attack is read-only, there is no write capability and no access to Secrets, ConfigMaps, or other resource types beyond these three. The attacker could read for example:
- Namespace names and labels.
- Services across all namespaces with ClusterIPs and ports to reveal cluster internal topology.
- Ingresses across all namespaces with hostnames and routing rules.
Patches
The vulnerable, already deprecated host-capabilities (kubernetes/ingresses, kubernetes/namespaces, kubernetes/services)
have been removed.
The removed calls were not being exercised by any Kubewarden SDK.
These host-callbacks had already been superseded for a long time by kubewarden/kubernetes/list_resources_by_namespace, kubewarden/kubernetes/list_resources, and kubewarden/kubernetes/get_resource. They provide similar capabilities while being more fine-grained, performant, and gated through our context-aware permissions feature. These current host-capabilities are part of the Kubernetes capabilities listed in our docs.
Workarounds
Kubewarden operators can update the policy-server image used by their PolicyServers to tag :v1.33.0.
Alternatively, Kubewarden operators can temporarily reduce the permissions of users to prevent them from creating or updating existing namespaced AdmissionPolicies or AdmissionPolicyGroups.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/kubewarden/kubewarden-controller | all versions | 1.33.0go get github.com/kubewarden/kubewarden-controller@v1.33.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/kubewarden/kubewarden-controller, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/kubewarden/kubewarden-controller to 1.33.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-29773 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-2026-29773 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-29773. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-29773 in your dependencies?
O3 Security finds CVE-2026-29773 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.