CVE-2025-11234: Use After Free

The vulnerability CVE-2025-11234 is a use-after-free flaw in the VNC WebSocket handshake implementation of the qemu-kvm user-space component used in Red Hat Enterprise Linux 9. This component enables full virtualization on Linux systems. The flaw could potentially lead to memory corruption issues. Red Hat has released an update as part of OpenShift Container Platform 4.12.97 and Red Hat Enterprise Linux 9 updates to fix this vulnerability. The advisory rates the security impact as moderate and provides detailed remediation instructions in the official Red Hat advisory.

The vulnerability could allow an attacker to exploit a use-after-free condition during the VNC WebSocket handshake in qemu-kvm, potentially leading to memory corruption. Red Hat rates this issue as moderate severity. There are no known exploits in the wild at this time. The impact is limited to systems running the affected qemu-kvm versions on Red Hat Enterprise Linux 9.

Red Hat has released an official security update that fixes this vulnerability. Users should apply the Red Hat Enterprise Linux 9 update containing the fixed qemu-kvm package as described in the Red Hat advisory RHSA-2026:18772. Follow the instructions at https://access.redhat.com/articles/11258 to apply the update. No additional mitigations are required beyond applying the official patch.