Medium 5.5Published May 13, 2026

CVE-2026-43483KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated

Updated under an hour ago (Oct 27, 2026, 5:50 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated Explicitly set/clear CR8 write interception when AVIC is (de)activated to fix a bug where KVM leaves the interception enabled after AVIC is activated. E.g. if KVM emulates INIT=>WFS while AVIC is deactivated, CR8 will remain intercepted in perpetuity. On its own, the dangling CR8 intercept is "just" a performance issue, but combined with the TPR sync bug fixed by commit d02e48830e3f ("KVM: SVM: Sync TPR from LAPIC into VMCB::V_TPR even if AVIC is active"), the danging intercept is fatal to Windows guests as the TPR seen by hardware gets wildly out of sync with reality. Note, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored when Virtual Interrupt Delivery is enabled, i.e. when APICv is active in KVM's world. I.e. there's no need to trigger update_cr8_intercept(), this is firmly an SVM implementation flaw/detail. WARN if KVM gets a CR8 write #VMEXIT while AVIC is active, as KVM should never enter the guest with AVIC enabled and CR8 writes intercepted. [Squash fix to avic_deactivate_vmcb. - Paolo]

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 13, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 3bbf3565f48ce3999b5a12cde946f81bd4475312 before a4123fe5d9122eef9852e4921f7cc463420f30d4; from 3bbf3565f48ce3999b5a12cde946f81bd4475312 before 816fa1dfae4532e851b1fe6b2434c753ecbd86c7; from 3bbf3565f48ce3999b5a12cde946f81bd4475312 before 01651e7751edbbc0fb4598f8367a3dabcfc8c182; from 3bbf3565f48ce3999b5a12cde946f81bd4475312 before ba3bca40f9f25c053f69413e5f4a41dd0fd762bf; from 3bbf3565f48ce3999b5a12cde946f81bd4475312 before 737410b32bd615b321da4fbeda490351b9af5e8b; from 3bbf3565f48ce3999b5a12cde946f81bd4475312 before 87d0f901a9bd8ae6be57249c737f20ac0cace93d	CNA record
linux linux_kernel linux:linux_kernel	from 4.7 before 6.1.167; from 6.2 before 6.6.130; from 6.7 before 6.12.78; from 6.13 before 6.18.19; from 6.19 before 6.19.9; 7.0; 7.0; 7.0	NVD

References

References

https://git.kernel.org/stable/c/a4123fe5d9122eef9852e4921f7cc463420f30d4	patch
https://git.kernel.org/stable/c/816fa1dfae4532e851b1fe6b2434c753ecbd86c7	patch
https://git.kernel.org/stable/c/01651e7751edbbc0fb4598f8367a3dabcfc8c182	patch
https://git.kernel.org/stable/c/ba3bca40f9f25c053f69413e5f4a41dd0fd762bf	patch
https://git.kernel.org/stable/c/737410b32bd615b321da4fbeda490351b9af5e8b	patch
https://git.kernel.org/stable/c/87d0f901a9bd8ae6be57249c737f20ac0cace93d	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.