CVE-2026-13218
MediumCVSS 4.2Exploitation Probability (EPSS)
Low risk1th percentile - higher than 1% of all known CVEs
Summary
A flaw in KubeVirt's virt-handler network cache handling allows a user with access to the virt-launcher container to overwrite arbitrary host files with JSON content and change their ownership by planting a symlink at the cache file path.
Risk Assessment
An attacker can overwrite critical host files, leading to privilege escalation, system integrity compromise, and potential full node takeover in KubeVirt environments.
Recommendation
Update KubeVirt to a patched version immediately and consider restricting access to the virt-launcher container using pod security policies.
Other vulnerabilities in KubeVirt
See all- CVE-2026-7374Critical
A flaw was found in KubeVirt's virt-handler component due to improper symlink validation when connecting to virtual machine console sockets. An authenticated OpenShift user with edit permissions in a single namespace can replace the console socket with a symlink to the host's CRI-O socket, hijacking virt-handler's privileged connection.
- CVE-2026-13622High
A symlink following vulnerability in KubeVirt's virt-handler migration proxy. During live migration, virt-handler dials Unix sockets inside the target virt-launcher pod via /proc/<pid>/root/ paths without symlink protection. An attacker with namespace edit and pods/exec permissions can replace a migration proxy socket with a symlink to the host CRI-O socket, enabling full node compromise.
- CVE-2026-13434Medium
A flaw in KubeVirt's network annotation generator allows a tenant with kubevirt.io:edit permissions to inject JSON into the v1.multus-cni.io/default-network annotation due to missing validation. When the ExternalNetResourceInjection feature gate is enabled (off by default), Multus can attach the pod to any network in any namespace.
- CVE-2026-13322Low
A flaw was found in KubeVirt's downward metrics virtio-serial server. The server reads guest requests using textproto.Reader.ReadLine(), which buffers input indefinitely until a newline character is received, with no length limit or read deadline. A user with access to a VM guest that has the downward metrics virtio-serial device configured can write a continuous byte stream to the device, causing unbounded memory allocation in the virt-handler process until it is OOM-killed.
- CVE-2026-13318Medium
A server-side request forgery (SSRF) flaw was found in KubeVirt's virt-api port-forward handler. When processing a port-forward request to a VirtualMachineInstance (VMI), virt-api reads the target IP from vmi.Status.Interfaces[0].IP and passes it directly to net.Dial() without validation. For VMIs using non-masquerade network bindings (bridge or secondary-only), this IP is reported by the QEMU guest agent running inside the VM and is fully controllable by the VM owner.
- CVE-2026-13208Medium
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.
- CVE-2026-13201High
A flaw in KubeVirt's safepath package, used by virt-handler, was found in the OpenAtNoFollow function. It uses O_PATH|O_NOFOLLOW to obtain a file descriptor, but subsequent operations resolve the path via /proc/self/fd/N using link-following syscalls. When the leaf is a symlink, the kernel dereferences it, bypassing the intended no-follow protection.
- CVE-2026-9804High
A path traversal vulnerability was found in KubeVirt's virt-exportserver component. An attacker with namespace-level access can place a symbolic link in an exported PVC pointing outside its mount root, allowing arbitrary file reads from the exporter pod's filesystem.
Original NVD description (English source)
A flaw was found in KubeVirt's virt-handler network cache handling. The WriteToCachedFile function writes data to a launcher-rooted path using os.WriteFile and os.Chown without symlink protection. A user with access to the virt-launcher container can plant a symlink at the cache file path, causing virt-handler to follow it and overwrite an arbitrary host file with JSON content and change its ownership.