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VulnerabilityPublished Updated

CVE-2026-46076: Linux kernel · KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1

Affects Linux kernelSource GCVE Database

0
Authoritative record:CVE-2026-46076· High 7.9

Not known to be exploited · CVSS 7.9 High · fixed in 6.8.0-1061.64~22.04.1 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.9High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.8.0-1061.64~22.04.1, 6.8.0-1063.71~22.04.1, 6.8.0-1062.69~22.04.1 +39
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-27.27
Fixed in
  • 7.0.0-27.27
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1008.8
Fixed in
  • 7.0.0-1008.8
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1010.10
Fixed in
  • 7.0.0-1010.10
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1009.9
Fixed in
  • 7.0.0-1009.9
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1007.7
Fixed in
  • 7.0.0-1007.7
Ubuntu 26.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=resoluteOther threatsAffected
  • <7.0.0-1009.9
Fixed in
  • 7.0.0-1009.9

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 and included in Linux kernel updates starting with version 7.0.0-27.27 and related builds. Users should update their Linux kernel to the fixed versions and reboot their systems to apply the changes. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary. Follow vendor guidance for updating and rebuilding kernel modules as needed.

Description

A vulnerability in the Linux kernel's KVM nested virtualization subsystem (nSVM) was resolved, addressing improper handling of unhandled VMMCALL instructions. Specifically, when L2 is active and L1 does not intercept certain VMMCALLs, KVM would intercept but not forward them, allowing L2 to execute hypercalls as if it were L1. This behavior deviates from architectural expectations, which require a #UD exception if VMMCALL is not intercepted. The issue has been fixed in updated Linux kernel versions. The vulnerability has a CVSS score of 7.9 (high severity) and affects numerous Linux kernel versions prior to the fixed releases. A patch is available and users are advised to update and reboot their systems.

References

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