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

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).

Published: 2026-04-24 Last update: 2026-04-27 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2026-31591 is rated Low Risk (4.1/100): low exploitation likelihood (EPSS 0.02%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-31591

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-25 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-31591

CVSS metrics for this CVE.

No CVSS data in dataset for this CVE.

Weakness enumeration for CVE-2026-31591

GitHub Security Advisory for CVE-2026-31591

GHSA-fvvw-8gw5-vw5f · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Lock all vCPUs...

OS Trackers for CVE-2026-31591

vendor priority summary link
debian unimportant CVE-2026-31591 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-31591
redhat medium https://access.redhat.com/security/cve/CVE-2026-31591
suse high https://www.suse.com/security/cve/CVE-2026-31591/
ubuntu medium CVE-2026-31591 medium priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1048, ignored 169, not-affected 112, released 83, needed 32, needs-triage 4, pending 1. https://ubuntu.com/security/CVE-2026-31591

Affected software / configurations for CVE-2026-31591

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-31591

cvelogic Threat Intelligence