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VulnerabilityPublished Updated

CVE-2026-98440: Linux kernel · KVM: arm64: nv: Delay freeing of shadow S2 structures until VM destruction

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.0 High · fixed in e5843f4effaa2ffac3e789ecd4456403564961d4 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
7.0High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in e5843f4effaa2ffac3e789ecd4456403564961d4, 876049f026b4dfaca0cc78ec81be0e639ca8525d, 22e82acec93a681071ed36f70eabe2d0c4e0bebd +1
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 18 Oct 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 e5843f4effaa2ffac3e789ecd4456403564961d4, 876049f026b4dfaca0cc78ec81be0e639ca8525d, 22e82acec93a681071ed36f70eabe2d0c4e0bebd or 5bf1c9175e657b3c2dc1cf77403031ac7aadcf66.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < e5843f4effaa2ffac3e789ecd4456403564961d4
Fixed in
  • e5843f4effaa2ffac3e789ecd4456403564961d4
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < 876049f026b4dfaca0cc78ec81be0e639ca8525d
Fixed in
  • 876049f026b4dfaca0cc78ec81be0e639ca8525d
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < 22e82acec93a681071ed36f70eabe2d0c4e0bebd
Fixed in
  • 22e82acec93a681071ed36f70eabe2d0c4e0bebd
LinuxLinuxAffected
  • ≥ 4f128f8e1aaac189f83d0f828bcdb2986d8d2e51, < 5bf1c9175e657b3c2dc1cf77403031ac7aadcf66
Fixed in
  • 5bf1c9175e657b3c2dc1cf77403031ac7aadcf66
LinuxLinuxAffected
  • =6.11
Fixed in–

AI-suggested

A fix is available and has been applied in the Linux kernel. Users should update to the fixed versions identified by the commits e5843f4effaa2ffac3e789ecd4456403564961d4, 876049f026b4dfaca0cc78ec81be0e639ca8525d, 22e82acec93a681071ed36f70eabe2d0c4e0bebd, and 5bf1c9175e657b3c2dc1cf77403031ac7aadcf66. Running the patched Linux kernel version 6.11 or later with these fixes applied will mitigate the vulnerability.

Description

CVE-2026-98440 is a high-severity vulnerability in the Linux kernel's KVM arm64 module. It involves improper timing of freeing shadow Stage 2 (S2) structures, which were previously freed prematurely during kvm_arch_flush_shadow_all(). This could lead to use-after-free conditions because the container structures might still be referenced elsewhere. The fix delays freeing these shadow S2 structures until the virtual machine (VM) is fully destroyed, ensuring that all references are safely removed.

References

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