---
title: "CVE-2026-89672: Linux Kernel NFSd - Broken Access Control"
description: "Linux kernel NFS server (nfsd) contains a broken access control vulnerability in NFSACL v2 SETACL path caused by improper handling of ACL mask bits, letting attackers silently remove ACLs, exploit requires crafted NFS SETACL requests."
url: https://panop.io/threat-heartbeat/CVE-2026-89672/
---

# CVE-2026-89672 Linux Kernel NFSd - Broken Access Control

Linux kernel NFS server (nfsd) contains a broken access control vulnerability in NFSACL v2 SETACL path caused by improper handling of ACL mask bits, letting attackers silently remove ACLs, exploit requires crafted NFS SETACL requests.

CVSS base score 9.1 /10

Critical

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.52% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89672)

## 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 nfsd SETACL mask handling.

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-2026-89672](https://nvd.nist.gov/vuln/detail/CVE-2026-89672)
- [https://git.kernel.org/stable/c/f951b22dbeec46f2e0fba81cb80d1b0c686b61eb](https://git.kernel.org/stable/c/f951b22dbeec46f2e0fba81cb80d1b0c686b61eb)
- [https://git.kernel.org/stable/c/8e4422b05f410f95c51b68a0db4bf1d87f6d22f5](https://git.kernel.org/stable/c/8e4422b05f410f95c51b68a0db4bf1d87f6d22f5)
- [https://git.kernel.org/stable/c/37eea38e7898538f0ec5f1eb8b18d8646e4be41c](https://git.kernel.org/stable/c/37eea38e7898538f0ec5f1eb8b18d8646e4be41c)
- [https://git.kernel.org/stable/c/a3a7e20ed66d3f04d37883c398da8a113b430769](https://git.kernel.org/stable/c/a3a7e20ed66d3f04d37883c398da8a113b430769)
- [https://git.kernel.org/stable/c/e41d173d9dc735cecb15ab7aa63ecab09338f81b](https://git.kernel.org/stable/c/e41d173d9dc735cecb15ab7aa63ecab09338f81b)

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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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