---
title: "CVE-2026-89671: Linux Kernel - Broken Access Control"
description: "Linux kernel contains a broken access control vulnerability in nfsd3_proc_setacl where ACL mask bits are not checked before setting ACLs, letting remote attackers unintentionally remove ACLs, exploit requires crafted NFSv3 SETACL request."
url: https://panop.io/threat-heartbeat/CVE-2026-89671/
---

# CVE-2026-89671 Linux Kernel - Broken Access Control

Linux kernel contains a broken access control vulnerability in nfsd3\_proc\_setacl where ACL mask bits are not checked before setting ACLs, letting remote attackers unintentionally remove ACLs, exploit requires crafted NFSv3 SETACL request.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.50% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89671)

## Details

Type

Broken Access Control

Impact

Broken Access Control

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for nfsd3\_proc\_setacl.

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-2026-89671](https://nvd.nist.gov/vuln/detail/CVE-2026-89671)
- [https://git.kernel.org/stable/c/b3bff820d068ea59767d4e91a3258231a879da5f](https://git.kernel.org/stable/c/b3bff820d068ea59767d4e91a3258231a879da5f)
- [https://git.kernel.org/stable/c/ff99ed007f065198fd723152405c22aa558f700b](https://git.kernel.org/stable/c/ff99ed007f065198fd723152405c22aa558f700b)
- [https://git.kernel.org/stable/c/3be1d8611dae4829e4608007db29f4a8748c37b2](https://git.kernel.org/stable/c/3be1d8611dae4829e4608007db29f4a8748c37b2)
- [https://git.kernel.org/stable/c/453d7198a0ab07a12d46e0575861ac7b932da17e](https://git.kernel.org/stable/c/453d7198a0ab07a12d46e0575861ac7b932da17e)
- [https://git.kernel.org/stable/c/68a80b26efdff1d09f8ae1773c6a915abb9e191d](https://git.kernel.org/stable/c/68a80b26efdff1d09f8ae1773c6a915abb9e191d)

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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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