---
title: "CVE-2026-89686: Linux Kernel - Denial of Service"
description: "Linux kernel contains a race condition in nfsd4_alloc_layout_stateid caused by unsynchronized access to fi_deleg_file during delegation revoke, letting NFS clients trigger a kernel BUG, exploit requires concurrent NFS clients with delegation and recall."
url: https://panop.io/threat-heartbeat/CVE-2026-89686/
---

# CVE-2026-89686 Linux Kernel - Denial of Service

Linux kernel contains a race condition in nfsd4\_alloc\_layout\_stateid caused by unsynchronized access to fi\_deleg\_file during delegation revoke, letting NFS clients trigger a kernel BUG, exploit requires concurrent NFS clients with delegation and recall.

CVSS base score 9.8 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.66% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89686)

## Details

Type

Denial of Service

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

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-89686](https://nvd.nist.gov/vuln/detail/CVE-2026-89686)
- [https://git.kernel.org/stable/c/97bda8b4284d90897a1f1922e5082ff9e35d7c7e](https://git.kernel.org/stable/c/97bda8b4284d90897a1f1922e5082ff9e35d7c7e)
- [https://git.kernel.org/stable/c/c517f27498757e616d2a8fe6d16caad1fee422e6](https://git.kernel.org/stable/c/c517f27498757e616d2a8fe6d16caad1fee422e6)
- [https://git.kernel.org/stable/c/ca94ba36172046be6a694a7986f6931e47ed4d51](https://git.kernel.org/stable/c/ca94ba36172046be6a694a7986f6931e47ed4d51)
- [https://git.kernel.org/stable/c/607a56fea772c1f4f4989d8e255dd4f7192d9604](https://git.kernel.org/stable/c/607a56fea772c1f4f4989d8e255dd4f7192d9604)

[← 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)