CVE-2026-46032
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk7th percentile - higher than 7% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel within KVM that occurs during nested #VMEXIT when loading L1's CR3 fails. In this case, the nested_svm_vmexit() function returns an error code that is ignored by most callers, leading to L1 continuing to run in a corrupted state.
Risk Assessment
Ignoring errors during nested #VMEXIT can lead to serious issues with the integrity of the virtual machine state, potentially resulting in system crashes. Organizations may experience unexpected downtime and data loss.
Recommendation
It is recommended to update the Linux kernel to the latest version to mitigate this vulnerability and ensure proper management of virtual machine states. Additionally, monitoring systems for any irregularities related to KVM operations is advised.
Original NVD description (English source)
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.