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Fencer Vulns
high 8.8

CVE-2026-46317 json

KVM: arm64: Reassign nested_mmus array behind mmu_lock

published 2026-06-09 5 mo ago modified 2026-10-19 20 d ago also EUVD-2026-35406

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 2%
public exploits
0
none known

Summary

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

KVM: arm64: Reassign nested_mmus array behind mmu_lock

kvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the MMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which can run at any time. kvm_vcpu_init_nested() reallocates the array and frees the old buffer while holding only kvm->arch.config_lock, so such a walker can reference the freed array.

Allocate the new array outside of mmu_lock, as the allocation can sleep. Under the lock, copy the existing entries, fix up the back pointers and reassign the array. Free the old buffer after dropping the lock, as kvfree() can sleep as well.

Patch / fix

  • Linux Linux 6.18.35, 7.0.12, 7.1
  • linux Debian 14 7.0.12-1

debian advisories DEBIAN-CVE-2026-46317

  • linux Ubuntu 26.04 LTS 7.0.0-28.28
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1008.8
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1003.4
  • linux-ibm Ubuntu 26.04 LTS 7.0.0-1010.10
  • linux-azure Ubuntu 26.04 LTS 7.0.0-1010.10
  • linux-raspi Ubuntu 26.04 LTS 7.0.0-1015.15
  • linux-riscv Ubuntu 26.04 LTS 7.0.0-28.28.1

ubuntu advisories UBUNTU-CVE-2026-46317

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-687.55.1.el9_8
  • rv RHEL 9 5.14.0-687.55.1.el9_8
  • perf RHEL 9 5.14.0-687.55.1.el9_8
  • rtla RHEL 9 5.14.0-687.55.1.el9_8
  • libperf RHEL 9 5.14.0-687.55.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.55.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.55.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.55.1.el9_8

red hat advisories RHSA-2026:76739RHSA-2026:72624

  • kernel-rt Linux Micro 6.2 6.12.0-160000.35.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.35.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.35.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.35.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.35.1.160000.2.16
  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.35.1
  • kernel-azure SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.35.1
  • kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.35.1

suse advisories SUSE-SU-2026:22112-1SUSE-SU-2026:22127-1SUSE-SU-2026:22117-1SUSE-SU-2026:22099-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.35.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.35.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.35.1

opensuse advisories openSUSE-SU-2026:20965-1openSUSE-SU-2026:11014-1

  • kernel AlmaLinux 10 6.12.0-211.61.1.el10_2
  • rv AlmaLinux 10 6.12.0-211.61.1.el10_2
  • perf AlmaLinux 10 6.12.0-211.61.1.el10_2
  • rtla AlmaLinux 10 6.12.0-211.61.1.el10_2
  • libperf AlmaLinux 10 6.12.0-211.61.1.el10_2
  • kernel-rt AlmaLinux 10 6.12.0-211.61.1.el10_2
  • kernel-64k AlmaLinux 10 6.12.0-211.61.1.el10_2
  • kernel-core AlmaLinux 10 6.12.0-211.61.1.el10_2

almalinux advisories ALSA-2026:72624

  • kernel Rocky Linux 10 6.12.0-211.61.1.el10_2

rocky linux advisories RLSA-2026:72624

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46317 updated cvss 7.0

kernel: KVM: arm64: Reassign nested_mmus array behind mmu_lock

  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.55.1.el9_8, perf 5.14.0-687.55.1.el9_8, rtla 5.14.0-687.55.1.el9_8, python3-perf 5.14.0-687.55.1.el9_8, kernel-devel-matched 5.14.0-687.55.1.el9_8, kernel-64k-devel-matched 5.14.0-687.55.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:76739
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.61.1.el10_2, perf 6.12.0-211.61.1.el10_2, rtla 6.12.0-211.61.1.el10_2, python3-perf 6.12.0-211.61.1.el10_2, kernel-devel-matched 6.12.0-211.61.1.el10_2, kernel-64k-devel-matched 6.12.0-211.61.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.55.1.el9_8, kernel-64k 5.14.0-687.55.1.el9_8, kernel-core 5.14.0-687.55.1.el9_8, kernel-tools 5.14.0-687.55.1.el9_8, kernel-modules 5.14.0-687.55.1.el9_8, kernel-64k-core 5.14.0-687.55.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:76739
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.61.1.el10_2, kernel-64k 6.12.0-211.61.1.el10_2, kernel-core 6.12.0-211.61.1.el10_2, kernel-tools 6.12.0-211.61.1.el10_2, kernel-modules 6.12.0-211.61.1.el10_2, kernel-64k-core 6.12.0-211.61.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.55.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.55.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.55.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.55.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.55.1.el9_8
    fixed: vendor fix RHSA-2026:76739
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.61.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.61.1.el10_2
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.55.1.el9_8, kernel-rt-64k 5.14.0-687.55.1.el9_8, kernel-rt-core 5.14.0-687.55.1.el9_8, kernel-rt-modules 5.14.0-687.55.1.el9_8, kernel-rt-64k-core 5.14.0-687.55.1.el9_8, kernel-rt-debug-core 5.14.0-687.55.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:76739
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.61.1.el10_2, kernel-rt-64k 6.12.0-211.61.1.el10_2, kernel-rt-core 6.12.0-211.61.1.el10_2, kernel-rt-modules 6.12.0-211.61.1.el10_2, kernel-rt-64k-core 6.12.0-211.61.1.el10_2, kernel-rt-debug-core 6.12.0-211.61.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:72624
show 3 more
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.55.1.el9_8, kernel-rt-core 5.14.0-687.55.1.el9_8, kernel-rt-modules 5.14.0-687.55.1.el9_8, kernel-rt-debug-core 5.14.0-687.55.1.el9_8, kernel-rt-modules-core 5.14.0-687.55.1.el9_8, kernel-rt-debug-modules 5.14.0-687.55.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:76739
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.61.1.el10_2, kernel-rt-core 6.12.0-211.61.1.el10_2, kernel-rt-modules 6.12.0-211.61.1.el10_2, kernel-rt-debug-core 6.12.0-211.61.1.el10_2, kernel-rt-modules-core 6.12.0-211.61.1.el10_2, kernel-rt-debug-modules 6.12.0-211.61.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:72624
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.13% chance of exploitation in the next 30 days, higher than 2% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.