What is CVE-2026-31591?

CVE-2026-31591 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10, affecting Linux kernel versions from 6.11 onward and patched in 6.18.24, 6.19.14, 7.0.1 and others. CVE-2026-31591 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-31591?

CVE-2026-31591 has a CVSS score of 5.5 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Is there a patch available for CVE-2026-31591?

Yes, CVE-2026-31591 has been patched. Fixed versions include 6.18.24, 6.19.14, 7.0.1 and others. If you are running Linux kernel 6.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-31591 actively exploited?

CVE-2026-31591 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-31591

Medium

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).

Package Linux Kernel

Published 2026-04-24

Last modified 2026-04-28

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

5.5

out of 10

Medium

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected versions

Linux kernel versions 6.11 and later are affected. Fixed in 6.18.24, 6.19.14, 7.0.1, 7.1-rc1 and their respective stable series.

Affected from

≥ 6.11

Fixed in

✓ 6.18.24 6.18.x ✓ 6.19.14 6.19.x ✓ 7.0.1 7.0.x ✓ 7.1-rc1

References

The following references provide additional information about CVE-2026-31591 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Kernel patch commit
https://git.kernel.org/stable/c/30fd9d8c82087742168db779929d8be0459b0716
Patch
Kernel patch commit
https://git.kernel.org/stable/c/4df77742e8b9a6b935bdf46f02fd0aca4d4ee7f5
Patch
Kernel patch commit
https://git.kernel.org/stable/c/c87938fc7d99a06a7e5477c45b4e5a4148f85d66
Patch

4 patch commits total View all on NVD

Details

CVE ID CVE-2026-31591

Severity Medium

CVSS score 5.5 / 10

CVSS version 3.1

Published 2026-04-24

Modified 2026-04-28

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-31591?

CVE-2026-31591 is a Medium severity Linux kernel vulnerability with a CVSS score of 5.5 out of 10 . It affects Linux kernel versions from 6.11 onward and has been patched in 6.18.24, 6.19.14, 7.0.1 and others. CVE-2026-31591 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-31591?

CVE-2026-31591 has a CVSS score of 5.5 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Is there a patch available for CVE-2026-31591?

Yes — CVE-2026-31591 has been patched. Fixed versions include 6.18.24, 6.19.14, 7.0.1 and others. If you are running Linux kernel 6.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-31591 actively exploited?

No — CVE-2026-31591 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.