Medium [CVE-2026-13208] virt-handler notify server trusts VMI identity from unauthenticated gRPC request body
This medium-severity Red Hat Linux advisory covers CVE-2026-13208 affecting Red Hat OpenShift Virtualization 4.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
VulniPulse record published Record updated
Summary
A flaw was found in KubeVirt's virt-handler domain notify server. The gRPC handlers for HandleDomainEvent and HandleK8SEvent derive the VMI identity (namespace/name) solely from the request body without validating it against the connection's origin.
Each virt-launcher pod connects through a per-VMI pipe socket, but no identity tag is propagated from the pipe path to the server handlers.
This allows a compromised virt-launcher process to send forged domain lifecycle events for any other VMI scheduled on the same node, causing virt-handler to erroneously update that VMI's state and disrupt its lifecycle management. Red Hat has assessed this issue as Moderate impact for OpenShift Virtualization.
In a default deployment, a user with namespace edit permissions can exec into their own virt-launcher pod and exploit the unvalidated VMI identity in the notify server to disrupt co-located VMs belonging to other tenants. The attack is limited to denial of service (forced shutdown/restart of targeted VMs) and does not provide data access or code execution.
Exploitation requires: (1) shell access inside a virt-launcher pod on the target node, (2) knowledge of the victim VMI's namespace and name, and (3) the victim VM to be scheduled on the same node.
Affected product named by the advisory: Red Hat OpenShift Virtualization 4.
Is CVE-2026-13208 exploited?
No exploitation is reported in the sources VulniPulse tracks: CVE-2026-13208 is not in the CISA KEV catalog (checked ) and this advisory does not report exploitation. That is not proof the vulnerability cannot be exploited.
How do I fix CVE-2026-13208?
The advisory VulniPulse tracks names no fixed release. Follow Red Hat's guidance for workarounds and updates.
Confirm against the vendor advisory before you patch.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.
Official advisory · high-confidence parse· fetched 15 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 15 days ago·verify at source
Mitigation checklist
- Organizations can reduce exposure by: (1) restricting pods/exec permission on virt-launcher pods via admission policies (e.g., Gatekeeper or Kyverno rules denying exec on pods with the kubevirt.io launcher label), (2) using node affinity or dedicated node pools to isolate high-security tenant workloads from untrusted tenants, and (3) monitoring for unexpected VMI state transitions via cluster alerting.
Official advisory · high-confidence parse· fetched 15 days ago·verify at source
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