---
title: "CVE-2026-89643: Linux Kernel - Use After Free"
description: "Linux kernel contains a use-after-free vulnerability in audit_del_rule() caused by improper handling of tree references during fsnotify rule autoremove, letting attackers cause system instability or denial of service, exploit requires triggering fsnotify autoremove."
url: https://panop.io/threat-heartbeat/CVE-2026-89643/
---

# CVE-2026-89643 Linux Kernel - Use After Free

Linux kernel contains a use-after-free vulnerability in audit\_del\_rule() caused by improper handling of tree references during fsnotify rule autoremove, letting attackers cause system instability or denial of service, exploit requires triggering fsnotify autoremove.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

EPSS

0.71% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89643)

## Details

Type

Use After Free

Impact

Denial Of Service

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version with the audit\_del\_rule() 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-2026-89643](https://nvd.nist.gov/vuln/detail/CVE-2026-89643)
- [https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d](https://git.kernel.org/stable/c/783f0f0974c156aca630f4ffff248671082a098d)
- [https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28](https://git.kernel.org/stable/c/cf37b61b5420fd4600fe78cf8c24da6e4d9bfe28)
- [https://git.kernel.org/stable/c/01b0ec8c397be65ff710777c97017ca1de56ef8e](https://git.kernel.org/stable/c/01b0ec8c397be65ff710777c97017ca1de56ef8e)
- [https://git.kernel.org/stable/c/695c85dc345a4e0292739f004c261bedef3f27e6](https://git.kernel.org/stable/c/695c85dc345a4e0292739f004c261bedef3f27e6)
- [https://git.kernel.org/stable/c/9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58](https://git.kernel.org/stable/c/9cac21f8eb82675ed19fb955b8bbb9dd14cc3d58)
- [https://git.kernel.org/stable/c/b322cc7adcd2e6ec1594d187533a126506ab545c](https://git.kernel.org/stable/c/b322cc7adcd2e6ec1594d187533a126506ab545c)
- [https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec](https://git.kernel.org/stable/c/583cf579b32d99e3fe4e9c8ecc4d852e3708fbec)
- [https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e](https://git.kernel.org/stable/c/636a99bab36ba27515363d325866c0273ac83b3e)

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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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