CVE-2026-98720: Linux kernel · KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 2.1 High.
Data as of 28 Oct 2026, 01:28 UTC
CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2026-98720 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98720 (opens in a new tab)
- git.kernel.org/stable/c/2db11598b59f16ddb6420693f9a4ac4efc3d4789 (opens in a new tab)
- git.kernel.org/stable/c/f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3a (opens in a new tab)
- git.kernel.org/stable/c/1e497e3bdab6983deb68a1d26b488027deb4527f (opens in a new tab)
- git.kernel.org/stable/c/2abb25273c82061dd4670690c81c319c03740bf6 (opens in a new tab)