CVE-2026-98440: Linux kernel · KVM: arm64: nv: Delay freeing of shadow S2 structures until VM destruction
Affects Linux kernelSource CVE Database V5
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| 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
- git.kernel.org/stable/c/876049f026b4dfaca0cc78ec81be0e639ca8525d (opens in a new tab)
- git.kernel.org/stable/c/22e82acec93a681071ed36f70eabe2d0c4e0bebd (opens in a new tab)
- git.kernel.org/stable/c/5bf1c9175e657b3c2dc1cf77403031ac7aadcf66 (opens in a new tab)
- git.kernel.org/stable/c/e5843f4effaa2ffac3e789ecd4456403564961d4 (opens in a new tab)