---
title: "CVE-2026-89930: Linux Kernel KVM - Broken Access Control"
description: "Linux kernel KVM nVMX contains a broken access control vulnerability caused by missing local TLB flushes on failed nested VM-Enter, letting attackers cause stale TLB entries leading to potential privilege escalation, exploit requires nested virtualization environment."
url: https://panop.io/threat-heartbeat/CVE-2026-89930/
---

# CVE-2026-89930 Linux Kernel KVM - Broken Access Control

Linux kernel KVM nVMX contains a broken access control vulnerability caused by missing local TLB flushes on failed nested VM-Enter, letting attackers cause stale TLB entries leading to potential privilege escalation, exploit requires nested virtualization environment.

CVSS base score 9.3 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.18% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89930)

## Details

Type

Broken Access Control

Impact

Privilege Escalation

CVSS vector

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

Published

16 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for TLB flush handling on failed nested VM-Enter.

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-2026-89930](https://nvd.nist.gov/vuln/detail/CVE-2026-89930)
- [https://git.kernel.org/stable/c/62c3ee4c9f0e2efef5157358b3549e50ede96d73](https://git.kernel.org/stable/c/62c3ee4c9f0e2efef5157358b3549e50ede96d73)
- [https://git.kernel.org/stable/c/c0c66cd575e31218da6a7d104c6ef80b0830b60c](https://git.kernel.org/stable/c/c0c66cd575e31218da6a7d104c6ef80b0830b60c)
- [https://git.kernel.org/stable/c/c43563e7518e65ec6ccaa6a65f84c5af5ca5d379](https://git.kernel.org/stable/c/c43563e7518e65ec6ccaa6a65f84c5af5ca5d379)
- [https://git.kernel.org/stable/c/f74fccdf4f7fb0780cd84944108d35f3d9dc46a7](https://git.kernel.org/stable/c/f74fccdf4f7fb0780cd84944108d35f3d9dc46a7)
- [https://git.kernel.org/stable/c/05a0b701d1089fb57beeb8982f23c3bbafe0fa8b](https://git.kernel.org/stable/c/05a0b701d1089fb57beeb8982f23c3bbafe0fa8b)
- [https://git.kernel.org/stable/c/1025b938dc439b75c720a568a855a13eeb245686](https://git.kernel.org/stable/c/1025b938dc439b75c720a568a855a13eeb245686)
- [https://git.kernel.org/stable/c/312cdb6d8940827dea63a7a52fb714a5049f06d1](https://git.kernel.org/stable/c/312cdb6d8940827dea63a7a52fb714a5049f06d1)

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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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