CVE-2026-31591 KVM: SEV: Lock all vCPUs when synchronzing VMSAs for SNP launch finish

What is CVE-2026-31591?

CVE-2026-31591 is a medium-severity vulnerability in Linux kernel, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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

KVM: SEV: Lock all vCPUs when synchronzing VMSAs for SNP launch finish

Lock all vCPUs when synchronizing and encrypting VMSAs for SNP guests, as allowing userspace to manipulate and/or run a vCPU while its state is being synchronized would at best corrupt vCPU state, and at worst crash the host kernel.

Opportunistically assert that vcpu->mutex is held when synchronizing its VMSA (the SEV-ES path already locks vCPUs).

Which versions are affected by CVE-2026-31591?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-31591?

Apply the vendor's patch.

Is CVE-2026-31591 being exploited?

There is no known exploitation of CVE-2026-31591 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-83819, BELL-CVE-2026-31591, DEBIAN-CVE-2026-31591, GHSA-fvvw-8gw5-vw5f, ROOT-OS-DEBIAN-11-CVE-2026-31591, ROOT-OS-DEBIAN-12-CVE-2026-31591 and 2 more.