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VulnerabilityPublished Updated

CVE-2026-46317: Linux kernel · KVM: arm64: Reassign nested_mmus array behind mmu_lock

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High · fixed in 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8, 918450ad6010df6ecd2efde12a1409e011da22d6, 4424dbcb06d68e34e51c019a5781a7dc00731971
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Jun 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 Linux kernel to 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8, 918450ad6010df6ecd2efde12a1409e011da22d6 or 4424dbcb06d68e34e51c019a5781a7dc00731971.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8
Fixed in
  • 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < 918450ad6010df6ecd2efde12a1409e011da22d6
Fixed in
  • 918450ad6010df6ecd2efde12a1409e011da22d6
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < 4424dbcb06d68e34e51c019a5781a7dc00731971
Fixed in
  • 4424dbcb06d68e34e51c019a5781a7dc00731971
LinuxLinuxAffected
  • =6.11
Fixed in–

Description

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.

References

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