CVE-2026-46032: KVM: nSVM: Triple fault if restore host CR3 fails on nested #VMEXIT

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-30

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.

Affected products

Linux kernel: from 5.9 before 7.0.4 — fixed in 7.0.4
Linux: 5.9 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 7.0.4; Linux 7.1. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-46032 or the next vulnerability affects your stack