CVE-2026-46071
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
A vulnerability in the Linux kernel related to KVM and nSVM has been resolved, concerning the improper clearing of VMCB_LBR in vmcb12. The svm_copy_lbrs() function always marked VMCB_LBR as dirty in the destination VMCB, leading to architecturally undefined behavior.
Risk Assessment
This vulnerability could lead to unpredictable effects on the operation of virtualization systems, potentially impacting the stability and security of virtual environments.
Recommendation
It is recommended to update the Linux kernel to the latest version to eliminate this vulnerability and to monitor virtual systems for any irregular behavior.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12 svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB. However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and clearing clean bits in vmcb12 is not architecturally defined. Move vmcb_mark_dirty() to callers and drop it for vmcb12. This also facilitates incoming refactoring that does not pass the entire VMCB to svm_copy_lbrs().