CVE-2026-31593

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU

Reject synchronizing vCPU state to its associated VMSA if the vCPU has

already been launched, i.e. if the VMSA has already been encrypted. On a

host with SNP enabled, accessing guest-private memory generates an RMP #PF

and panics the host.

BUG: unable to handle page fault for address: ff1276cbfdf36000

#PF: supervisor write access in kernel mode

#PF: error_code(0x80000003) - RMP violation

PGD 5a31801067 P4D 5a31802067 PUD 40ccfb5063 PMD 40e5954063 PTE 80000040fdf36163

SEV-SNP: PFN 0x40fdf36, RMP entry: [0x6010fffffffff001 - 0x000000000000001f]

Oops: Oops: 0003 [#1] SMP NOPTI

CPU: 33 UID: 0 PID: 996180 Comm: qemu-system-x86 Tainted: G OE

Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE

Hardware name: Dell Inc. PowerEdge R7625/0H1TJT, BIOS 1.5.8 07/21/2023

RIP: 0010:sev_es_sync_vmsa+0x54/0x4c0 [kvm_amd]

Call Trace:

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References