CVE-2026-46032 KVM: nSVM: Triple fault if restore host CR3 fails on nested #VMEXIT
A flaw in Linux KVM nested SVM handling causes a triple fault and system crash when host CR3 restoration fails during a nested VM exit.
- 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-2026-46032?
CVE-2026-46032 is a medium-severity denial of service vulnerability in Linux kernel, published on 27 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: nSVM: Triple fault if restore host CR3 fails on nested #VMEXIT
If loading L1's CR3 fails on a nested #VMEXIT, nested_svm_vmexit() returns an error code that is ignored by most callers, and continues to run L1 with corrupted state. A sane recovery is not possible in this case, and HW behavior is to cause a shutdown. Inject a triple fault instead, and do not return early from nested_svm_vmexit(). Continue cleaning up the vCPU state (e.g. clear pending exceptions), to handle the failure as gracefully as possible.
From the APM:
Upon #VMEXIT, the processor performs the following actions in order to return to the host execution context:
...
if (illegal host state loaded, or exception while loading host state) shutdown else execute first host instruction following the VMRUN
Remove the return value of nested_svm_vmexit(), which is mostly unchecked anyway.
Which versions are affected by CVE-2026-46032?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46032?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-46032 being exploited?
There is no known exploitation of CVE-2026-46032 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88487, BELL-CVE-2026-46032, DEBIAN-CVE-2026-46032, GHSA-rgj9-vx7j-x86j, ROOT-OS-DEBIAN-11-CVE-2026-46032, ROOT-OS-DEBIAN-12-CVE-2026-46032 and 4 more.