CVE-2026-46071: Linux kernel · KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 7.0.0-28.28~24.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-28.28~24.04.1, 7.0.0-27.27, 7.0.0-1008.8 +6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 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
Upgrade to a fixed release listed under Affected software.
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-ibmpkg:deb/ubuntu/linux-ibm?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.
AI-suggested
A patch is available from the vendor and should be applied to affected linux-hwe-edge kernel versions. The vendor advisory confirms the availability of fixes. Users should update to the patched kernel versions to remediate this vulnerability.
Description
A medium severity vulnerability (CVE-2026-46071) in the Linux kernel's KVM nested SVM (nSVM) implementation was resolved. The issue involved improper handling of the VMCB_LBR dirty bit in the svm_copy_lbrs() function, which could cause undefined behavior. This flaw was fixed by adjusting the management of the dirty bit in nested virtual machine control blocks. Multiple linux-hwe-edge kernel versions prior to specific patched releases are affected. A patch is available from the vendor.
References
- ubuntu.com/security/CVE-2026-46071 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46071 (opens in a new tab)
- git.kernel.org/linus/b53ab5167a81537777ac780bbd93d32613aa3bda (opens in a new tab)
- ubuntu.com/security/notices/USN-8488-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8489-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8488-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8507-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)