CVE-2026-43315

A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem for AMD processors. A local attacker with permission to manage virtual machines can trigger a Denial of Service (DoS) by submitting an inconsistent processor state during nested virtualization operations. This action triggers an unexpected kernel warning, which can cause the host system to crash if configured to treat kernel warnings as fatal errors.

Red Hat has evaluated this vulnerability as having a Moderate impact because exploitation requires local access with permissions to interact with the KVM subsystem on AMD hardware, limiting the attack surface to authorized users or compromised VM management processes. A local attacker can invoke specific KVM control requests to trigger a kernel warning, which does not allow privilege escalation or data leakage but may cause a denial of service if the host kernel is configured to treat warnings as fatal. Systems without AMD nested virtualization enabled or hosts where access to the KVM device is restricted to trusted administrative users are not exposed to this issue.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.