CVE-2026-99177

A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem. This vulnerability may lead to a Denial of Service (DoS) due to improper locking when marking guest memory pages as modified during AMD Secure Encrypted Virtualization (SEV) operations. A local user with permissions to manage virtual machines could trigger a race condition where memory mappings concurrently disappear, resulting in memory corruption and a system crash.

This vulnerability is rated as Moderate impact for Red Hat because exploitation requires local privileges to manage virtual machines on AMD hardware utilizing Secure Encrypted Virtualization (SEV). In standard Red Hat Enterprise Linux environments, unprivileged users do not have direct access to KVM device interfaces, limiting exposure to authorized hypervisor operators. Furthermore, the potential impact is confined to host denial of service through a system crash, without enabling data leakage or integrity compromise.

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.