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().

A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) subsystem, specifically affecting its nested virtualization (nSVM) capabilities. The issue arises from incorrect handling of Virtual Machine Control Block Last Branch Record (VMCB_LBR) data when copied to vmcb12, an operation that is not architecturally defined. This can lead to unexpected behavior or instability within nested virtualized environments, potentially impacting the reliability of guest virtual machines.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-46071 https://nvd.nist.gov/vuln/detail/CVE-2026-46071 https://lore.kernel.org/linux-cve-announce/2026052758-CVE-2026-46071-d16a@gregkh/T