What’s Vulnerable › Vulnerabilities

CVE-2026-46071: KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12

• 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: 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().

Affected products

• Linux kernel: from 5.19 before 6.18.27; from 6.19 before 7.0.4 — fixed in 6.18.27, 7.0.4
• Linux: 5.19 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 6.18.27, 7.0.4; Linux 7.1. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/11d347b7edf5093d69aca72317300798a32bfd6b
• https://git.kernel.org/stable/c/165b08d2d1346dce5ed43db65e10f3194b9ae2fe
• https://git.kernel.org/stable/c/9efe23568806d1cd06f7d146f9b3037b8d585a9f
• https://git.kernel.org/stable/c/a3f0981a5a0e0bd51ad74cc7d9eed32294b24002
• https://git.kernel.org/stable/c/b53ab5167a81537777ac780bbd93d32613aa3bda
• https://git.kernel.org/stable/c/b7fefb393a926bdfe445c63b4091185ed7da2733

Get alerted when CVE-2026-46071 or the next vulnerability affects your stack