CVE-2026-64604: Linux kernel · KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode
Affects Linux kernelSource GCVE Database
Not known to be exploited · fixed in 5.15.0-1117.124~20.04.1 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:49 UTC
Rated by Threat Radar · CVSS not yet scored by NVD
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +58
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Aug 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.
Patches and advisories
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
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.
AI-suggested
A fix is available and included in Linux kernel versions 5.15.0-1117.124~20.04.1 and later patched releases. Users should update to these fixed kernel versions to resolve the issue. No additional mitigation actions are required.
Description
A vulnerability in the Linux kernel's KVM VMX subsystem was fixed, involving the conditional grabbing of vmcs12 on CR8 interception updates only when the vCPU is in guest mode. This fix prevents lock dependency assertion failures during vCPU creation. The issue does not cause functional changes but addresses a kernel locking correctness problem.
References
- ubuntu.com/security/CVE-2026-64604 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64604 (opens in a new tab)
- git.kernel.org/linus/7ef78d71ca713d8c00f7c34ddcf276c808143f77 (opens in a new tab)
- git.kernel.org/stable/c/258ec63c0f281bf7b50f9de67c8e93b5b7be5ed4 (opens in a new tab)
- git.kernel.org/stable/c/3dcfb04dd43b16fa1240fc6487fff578ad57264c (opens in a new tab)
- git.kernel.org/stable/c/570af5db081b87374594a00711ac5760d2ea6844 (opens in a new tab)
- git.kernel.org/stable/c/7ef78d71ca713d8c00f7c34ddcf276c808143f77 (opens in a new tab)
- git.kernel.org/stable/c/9a21f1defd96c6301c5fb462a78eb51b191bd2dd (opens in a new tab)
- git.kernel.org/stable/c/c7cd3605244c924249dea32632e1bc3e89bda543 (opens in a new tab)
- git.kernel.org/stable/c/db8407b9fd06d857a4a5e8bcff1d086d13007711 (opens in a new tab)
- git.kernel.org/stable/c/ffaaff82336db84e9b58e7a3e81c2fd64e05ed7a (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)