---
title: "CVE-2026-99082: Linux Kernel KVM - Cache Invalidation Bypass"
description: "Linux kernel KVM x86 contains a stale MMIO cache caused by improper use of memslots in SMM address space, letting a guest cause invalid MMIO exits and bypass write-tracking, exploit requires nested EPT and crafted memory access."
url: https://panop.io/threat-heartbeat/CVE-2026-99082/
---

# CVE-2026-99082 Linux Kernel KVM - Cache Invalidation Bypass

Linux kernel KVM x86 contains a stale MMIO cache caused by improper use of memslots in SMM address space, letting a guest cause invalid MMIO exits and bypass write-tracking, exploit requires nested EPT and crafted memory access.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.21% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-99082)

## Details

Type

Cache Invalidation Bypass

Impact

Denial Of Service, Data Tampering

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Published

23 October 2026

Updated

25 October 2026

## Vendor fix

Update to the latest Linux kernel mainline version containing the fix.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-99082](https://nvd.nist.gov/vuln/detail/CVE-2026-99082)
- [https://git.kernel.org/stable/c/e792a9ace39d2812a5b342a1987186c7bc653204](https://git.kernel.org/stable/c/e792a9ace39d2812a5b342a1987186c7bc653204)
- [https://git.kernel.org/stable/c/2566780c684c9c21241d409d790087c73070f312](https://git.kernel.org/stable/c/2566780c684c9c21241d409d790087c73070f312)
- [https://git.kernel.org/stable/c/7fd4e64f4bbc8c35ae8f0d2a1fb5b77a76d5b4fd](https://git.kernel.org/stable/c/7fd4e64f4bbc8c35ae8f0d2a1fb5b77a76d5b4fd)
- [https://git.kernel.org/stable/c/a63f79d9da9468952396af73e1e53330845cf876](https://git.kernel.org/stable/c/a63f79d9da9468952396af73e1e53330845cf876)
- [https://git.kernel.org/stable/c/b3e6212dea2e4328a841ceb37f377583176dc735](https://git.kernel.org/stable/c/b3e6212dea2e4328a841ceb37f377583176dc735)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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