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High · 7.9 CVE-2026-46076 EUVD-2026-32458GHSA-gj33-hwgc-v3v8

KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1

Published May 27, 2026 · Updated Oct 21, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.2 Package: linux-azure-fde-6.8 Package: linux-azure-fips Package: linux-azure-nvidia Package: linux-azure-nvidia-6.14 Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.17 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-7.0 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-nvidia Package: linux-nvidia-6.11 Package: linux-nvidia-6.17 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.17 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oem-7.0 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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

KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1

Explicitly synthesize a #UD for VMMCALL if L2 is active, L1 does NOT want
to intercept VMMCALL, nested_svm_l2_tlb_flush_enabled() is true, and the
hypercall is something other than one of the supported Hyper-V hypercalls.
When all of the above conditions are met, KVM will intercept VMMCALL but
never forward it to L1, i.e. will let L2 make hypercalls as if it were L1.

The TLFS says a whole lot of nothing about this scenario, so go with the
architectural behavior, which says that VMMCALL #UDs if it's not
intercepted.

Opportunistically do a 2-for-1 stub trade by stub-ifying the new API
instead of the helpers it uses. The last remaining "single" stub will
soon be dropped as well.

[sean: rewrite changelog and comment, tag for stable, remove defunct stubs]

Affected products

VendorProductAffectedFixed
Linux Linux 6.2 6.6.160

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 7.0.4-1 —
Debian 13 linux 6.12.86-1 —
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 24.04 LTS linux-bluefield 6.8.0-1028.33 —
Ubuntu 26.04 LTS linux 7.0.0-27.27 USN-8488-1
Ubuntu 26.04 LTS linux-aws +1 7.0.0-1008.8 USN-8489-1, USN-8488-1
Ubuntu 26.04 LTS linux-azure 7.0.0-1010.10 USN-8603-1
Ubuntu 26.04 LTS linux-gcp +1 7.0.0-1007.7 USN-8488-1
Ubuntu 26.04 LTS linux-ibm +1 7.0.0-1009.9 USN-8603-1, USN-8488-1
Ubuntu 26.04 LTS linux-nvidia 7.0.0-1013.13 USN-8507-1
Ubuntu 26.04 LTS linux-raspi 7.0.0-1014.14 USN-8488-2
Ubuntu 26.04 LTS linux-riscv +1 7.0.0-27.27.1 USN-8488-1
Ubuntu 25.10 linux +8 No fix yet —
Ubuntu 24.04 LTS linux 6.8.0-136.136 USN-8567-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1061.64 USN-8595-2
Ubuntu 24.04 LTS linux-azure 6.8.0-1063.71 USN-8606-1
Ubuntu 24.04 LTS linux-azure-fde 6.8.0-1062.69 USN-8607-1
Ubuntu 24.04 LTS linux-gcp 6.8.0-1064.72 USN-8567-1
Ubuntu 24.04 LTS linux-gke 6.8.0-1059.67 USN-8567-1
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1046.50 USN-8567-1
Ubuntu 24.04 LTS linux-hwe-7.0 7.0.0-28.28~24.04.1 USN-8569-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1061.62 USN-8574-3
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-136.136.2 USN-8574-2
Ubuntu 24.04 LTS linux-nvidia 6.8.0-1059.62 USN-8596-1
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1059.62.1 USN-8596-1
Ubuntu 24.04 LTS linux-nvidia-tegra 6.8.0-1030.31 USN-8574-3
Ubuntu 24.04 LTS linux-oracle 6.8.0-1058.61 USN-8574-2
Ubuntu 24.04 LTS linux-raspi 6.8.0-1061.65 USN-8665-1
Ubuntu 24.04 LTS linux-riscv +27 No fix yet —
Ubuntu 24.04 LTS linux-vmware 6.8.0-1008.8 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1033.34 USN-8574-3
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1061.64~22.04.1 USN-8595-3
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1063.71~22.04.1 USN-8606-1
Ubuntu 22.04 LTS linux-azure-fde-6.8 6.8.0-1062.69~22.04.1 USN-8609-1
Ubuntu 22.04 LTS linux-gcp-6.8 6.8.0-1064.72~22.04.1 USN-8567-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-136.136~22.04.1 USN-8619-1
Ubuntu 22.04 LTS linux-ibm-6.8 6.8.0-1061.62~22.04.1 USN-8574-3
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-136.136.2~22.04.1 USN-8574-2
Ubuntu 22.04 LTS linux-nvidia-6.8 6.8.0-1059.62~22.04.1 USN-8596-1
Ubuntu 22.04 LTS linux-oracle-6.8 6.8.0-1058.61~22.04.1 USN-8595-1
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 6.8.0-136.136~22.04.3 —
Show 6 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2050.52 USN-8665-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1056.57 USN-8567-1
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 +1 No fix yet —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1056.57~22.04.2 USN-8567-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-aws-fips 6.8.0-1061.64+fips1 USN-8595-3
Ubuntu Pro FIPS-updates 24.04 LTS linux-azure-fips 6.8.0-1063.71+fips2 USN-8608-1
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-136.136+fips2 USN-8574-2
Ubuntu Pro FIPS-updates 24.04 LTS linux-gcp-fips 6.8.0-1064.72+fips1 USN-8574-1
ReleasePackageFixed inAdvisory
RHEL 10 rv +76 6.12.0-211.61.1.el10_2 RHSA-2026:72624
RHEL 9 rv +75 5.14.0-687.55.1.el9_8 RHSA-2026:76739

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 10 rv +74 6.12.0-211.61.1.el10_2 ALSA-2026:72624

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 10 kernel 6.12.0-211.61.1.el10_2 RLSA-2026:72624
ReleasePackageFixed inAdvisory
SLES 15 SP7 kernel-64kb +6 6.4.0-150700.53.66.1 SUSE-SU-2026:2800-1
SLES 15 SP7 kernel-default-base 6.4.0-150700.53.66.1.150700.17.39.1 SUSE-SU-2026:2800-1
SLES 15 SP7 kernel-docs 6.4.0-150700.53.66.2 SUSE-SU-2026:2800-1
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.125.1 SUSE-SU-2026:3156-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.125.1.150600.12.58.3 SUSE-SU-2026:3156-1
Show 9 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLES for SAP 16.0 kernel-64kb +8 6.12.0-160000.36.1 SUSE-SU-2026:22835-1
SLES for SAP 16.0 kernel-default-base 6.12.0-160000.36.1.160000.2.17 SUSE-SU-2026:22835-1
SLES for SAP 15 SP6 kernel-default-base 6.4.0-150600.23.125.1.150600.12.58.3 SUSE-SU-2026:3156-1
SLES for SAP 15 SP6 kernel-docs +4 6.4.0-150600.23.125.1 SUSE-SU-2026:3156-1
SLES 16.0 kernel-64kb +8 6.12.0-160000.36.1 SUSE-SU-2026:22835-1, SUSE-SU-2026:22812-1
SLES 16.0 kernel-default-base 6.12.0-160000.36.1.160000.2.17 SUSE-SU-2026:22835-1
SLE Micro 6.2 kernel-default-base 6.12.0-160000.36.1.160000.2.17 SUSE-SU-2026:22769-1
SLE Micro 6.2 kernel-rt +5 6.12.0-160000.36.1 SUSE-SU-2026:22769-1, SUSE-SU-2026:22742-1
SLE Micro 6.1 kernel-rt +4 6.4.0-49.1 SUSE-SU-2026:22666-1, SUSE-SU-2026:22665-1
SLE Micro 6.0 kernel-rt +4 6.4.0-49.1 SUSE-SU-2026:22522-1, SUSE-SU-2026:22521-1
SLE Live Patching 15 SP7 kernel-default 6.4.0-150700.53.66.1 SUSE-SU-2026:2800-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7-RT_Update_17 1-150700.1.3.1 SUSE-SU-2026:2799-1
SLE Live Patching 15 SP7 kernel-livepatch-SLE15-SP7_Update_18 1-150700.15.3.1 SUSE-SU-2026:2800-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.125.1 SUSE-SU-2026:3156-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_29 1-150600.13.7.1 SUSE-SU-2026:3156-1
SUSE Real Time Module 15 SP7 kernel-rt +2 6.4.0-150700.7.62.1 SUSE-SU-2026:2799-1
ReleasePackageFixed inAdvisory
openSUSE Tumbleweed kernel-source 7.0.11-1.1 openSUSE-SU-2026:10954-1
openSUSE Leap 16.0 kernel-default-base 6.12.0-160000.36.1.160000.2.17 openSUSE-SU-2026:21388-1
openSUSE Leap 16.0 kernel-rt +11 6.12.0-160000.36.1 openSUSE-SU-2026:21388-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.18.30-61.116 +1 1:1.0-0.amzn2023 ALAS2023-2026-1754, ALAS2023-2026-1753
Amazon Linux 2023 perf6.12 +11 1:6.12.88-119.157.amzn2023 ALAS2023-2026-1753
Amazon Linux 2023 perf6.18 +11 1:6.18.30-61.116.amzn2023 ALAS2023-2026-1754

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 3 kernel No fix yet —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 10 rv +29 6.12.0-211.61.1.el10_2 ELSA-2026-72624
Oracle Linux 9 kernel-uek +34 6.12.0-204.92.4.2.el10uek ELSA-2026-50372
Oracle Linux 9 rv +28 5.14.0-687.56.1.el9_8 ELSA-2026-76739

Advisories 43

References