---
title: "CVE-2026-89908: Linux Kernel KVM - Memory Region Flags Preservation"
description: "Linux kernel KVM on LoongArch contains a memory region flags preservation vulnerability caused by improper handling of memslot arch flags during KVM_MR_FLAGS_ONLY updates, letting attackers cause incorrect memory mappings, exploit requires KVM_MR_FLAGS_ONLY update."
url: https://panop.io/threat-heartbeat/CVE-2026-89908/
---

# CVE-2026-89908 Linux Kernel KVM - Memory Region Flags Preservation

Linux kernel KVM on LoongArch contains a memory region flags preservation vulnerability caused by improper handling of memslot arch flags during KVM\_MR\_FLAGS\_ONLY updates, letting attackers cause incorrect memory mappings, exploit requires KVM\_MR\_FLAGS\_ONLY update.

CVSS base score 8.8 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.18% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89908)

## Details

Type

Memory Region Flags Preservation

Impact

Data Tampering, Denial Of Service

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/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.

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-2026-89908](https://nvd.nist.gov/vuln/detail/CVE-2026-89908)
- [https://git.kernel.org/stable/c/27a9bfee3bbcb3cabb77797354f07e0e44e49831](https://git.kernel.org/stable/c/27a9bfee3bbcb3cabb77797354f07e0e44e49831)
- [https://git.kernel.org/stable/c/4e4dbc341b1581dc512b85d98b768373b0398366](https://git.kernel.org/stable/c/4e4dbc341b1581dc512b85d98b768373b0398366)
- [https://git.kernel.org/stable/c/7c6df65b53846cd7a9a1c81c6ddb42fdc08603e8](https://git.kernel.org/stable/c/7c6df65b53846cd7a9a1c81c6ddb42fdc08603e8)
- [https://git.kernel.org/stable/c/bc7a6849b4395f45a602db91b0fb2fb2e9ed4bba](https://git.kernel.org/stable/c/bc7a6849b4395f45a602db91b0fb2fb2e9ed4bba)

[← All CVEs](https://panop.io/threat-heartbeat/)

## 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

Panop answers these inside your environment, for this CVE and every other finding.

[Book a demo](https://panop.io/demo)