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CVE-2026-98720

Linux: KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.17%Chance of exploitation activity in the next 30 days, higher than 5% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in2db11598b59f16ddb6420693f9a4ac4efc3d4789Also 1e497e3bdab6983deb68a1d26b488027deb4527f, 2abb25273c82061dd4670690c81c319c03740bf6CVE List
Published18 Oct 2026Updated 19 Oct 2026CVE List

What fixes it

  • 2db11598b59f16ddb6420693f9a4ac4efc3d4789LinuxCVE List
  • 1e497e3bdab6983deb68a1d26b488027deb4527fLinuxCVE List
  • 2abb25273c82061dd4670690c81c319c03740bf6LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

In the Linux kernel, the following vulnerability has been resolved:

KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified

Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the runtime eVMCS controls (pin, primary, secondary, etc.) are being updated. If L1 isn't intercepting TPR writes, runs L2 with TPR virtualization, and then runs the same L2 with TPR virtualization disabled, KVM will fail to refresh msr_bitmap02 and leave TPR in passthrough mode even though TPR virtualization is disabled. I.e. failure to refresh the bitmap lets L2 (or L1 by proxy) read and write L0's TPR.

Text from CVE List

Affected versions 10

  • Linuxaffected: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e before 2db11598b59f16ddb6420693f9a4ac4efc3d4789CVE List
  • Linuxaffected: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e before f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3aCVE List
  • Linuxaffected: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e before 1e497e3bdab6983deb68a1d26b488027deb4527fCVE List
  • Linuxaffected: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e before 2abb25273c82061dd4670690c81c319c03740bf6CVE List
  • Linuxaffected: 5.17CVE List
  • Linuxunaffected: all versions before 5.17CVE List
  • Linuxunaffected: 6.12.113 through 6.12.*CVE List
  • Linuxunaffected: 6.18.56 through 6.18.*CVE List
  • Linuxunaffected: 7.2.10 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 4