CVE-2026-13322 Kubevirt: virt-handler-rhel9: kubevirt: unbounded virtio-serial readline in virt-handler causes oom denial of service
An attacker with guest access can cause a denial of service in virt-handler by sending unbounded data to the virtio-serial device, leading to memory exhaustion.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-13322?
CVE-2026-13322 is a low-severity denial of service vulnerability in Red Hat OpenShift Virtualization 4, published on 26 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-770
Which versions are affected by CVE-2026-13322?
It affects 2 products.
Products include Kubevirt Kubevirt, Redhat Openshift Virtualization.
How do I fix CVE-2026-13322?
No fix has been published for CVE-2026-13322 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-13322 being exploited?
There is no known exploitation of CVE-2026-13322 in the wild and no public exploit code.
Other vulnerabilities in Red Hat OpenShift Virtualization 4
- CVE-2020-14316 Privilege Escalation in kubevirt
- CVE-2022-1798 Path Traversal vulnerability in Kubevirt
- CVE-2025-64324 KubeVirt Vulnerable to Arbitrary Host File Read and Write
- CVE-2023-26484 On a compromised KubeVirt node, the virt-handler service account can be used to modify all node specs
- CVE-2026-13201 Path traversal in Red Hat Container Native Virtualization 4.12
Sources
Also known as AZL-91454, GHSA-6f2p-2qg2-qqch, MINI-2fvj-hmpf-r7f4, MINI-5p38-r9qp-8p5h.