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.
Problem types
Allocation of Resources Without Limits or Throttling
Product status
Timeline
| 2026-06-25: | Reported to Red Hat. |
| 2026-06-25: | Made public. |
Credits
This issue was discovered by Huzaifa Sidhpurwala (Red Hat).
References
access.redhat.com/security/cve/CVE-2026-13322
bugzilla.redhat.com/show_bug.cgi?id=2492681 (RHBZ#2492681)