CVE-2026-99082: Linux kernel · KVM: x86: Use active memslots for the per-vCPU MMIO cache
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 8.8 High · fixed in e792a9ace39d2812a5b342a1987186c7bc653204 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:18 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in e792a9ace39d2812a5b342a1987186c7bc653204, b3e6212dea2e4328a841ceb37f377583176dc735, a63f79d9da9468952396af73e1e53330845cf876 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 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 to a fixed release listed under Affected software.
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
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
This vulnerability has been fixed in mainline Linux kernel versions identified by the provided commit hashes. Users and administrators should update their Linux kernels to versions including these fixes to resolve the issue. No additional mitigations are required once the kernel is patched.
Description
CVE-2026-99082 is a vulnerability in the Linux kernel's KVM x86 virtualization component related to the handling of per-vCPU MMIO cache and memslots in System Management Mode (SMM). The flaw allows stale MMIO cache entries from the SMM address space to remain valid after switching back to the normal address space, potentially causing incorrect memory writes that bypass KVM's write-tracking mechanisms. This can lead to inconsistent nested EPT table states and trigger kernel warnings. The issue is fixed by using the active memslots for caching and validation, ensuring proper separation of address spaces.
References
- git.kernel.org/stable/c/a63f79d9da9468952396af73e1e53330845cf876 (opens in a new tab)
- git.kernel.org/stable/c/7fd4e64f4bbc8c35ae8f0d2a1fb5b77a76d5b4fd (opens in a new tab)
- git.kernel.org/stable/c/2566780c684c9c21241d409d790087c73070f312 (opens in a new tab)
- git.kernel.org/stable/c/e792a9ace39d2812a5b342a1987186c7bc653204 (opens in a new tab)
- git.kernel.org/stable/c/b3e6212dea2e4328a841ceb37f377583176dc735 (opens in a new tab)