CVE-2026-46131 KVM: x86: check for nEPT/nNPT in slow flush hypercalls

Medium 5.5 Published Updated

A logic error in KVM hypercall handling when nested paging is disabled can lead to a denial of service in the Linux kernel.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
Available

What is CVE-2026-46131?

CVE-2026-46131 is a medium-severity vulnerability in Linux kernel, published on 28 May 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: x86: check for nEPT/nNPT in slow flush hypercalls

Checking is_guest_mode(vcpu) is incorrect, because translate_nested_gpa() is only valid if an L2 guest is running *with nested EPT/NPT enabled*. Instead use the same condition as translate_nested_gpa() itself.

Which versions are affected by CVE-2026-46131?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2026-46131?

Apply the vendor's patch.

Is CVE-2026-46131 being exploited?

There is no known exploitation of CVE-2026-46131 in the wild and no public exploit code.

All Linux kernel vulnerabilities

Sources

Also known as AZL-89009, BELL-CVE-2026-46131, DEBIAN-CVE-2026-46131, GHSA-3wqm-qqw5-qr42, ROOT-OS-UBUNTU-2404-CVE-2026-46131, UBUNTU-CVE-2026-46131.

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