---
title: "CVE-2026-89840: Linux kernel f2fs - Broken Access Control"
description: "Linux kernel contains a broken access control vulnerability in f2fs where F2FS_IOC_MOVE_RANGE does not validate destination size properly, letting attackers cause destination inode overflow, exploit requires ability to invoke MOVE_RANGE ioctl."
url: https://panop.io/threat-heartbeat/CVE-2026-89840/
---

# CVE-2026-89840 Linux kernel f2fs - Broken Access Control

Linux kernel contains a broken access control vulnerability in f2fs where F2FS\_IOC\_MOVE\_RANGE does not validate destination size properly, letting attackers cause destination inode overflow, exploit requires ability to invoke MOVE\_RANGE ioctl.

CVSS base score 7.1 /10

High

CISA KEV

Not listed

Public exploit

None known

EPSS

0.17% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89840)

## Details

Type

Broken Access Control

Impact

Broken Access Control

CVSS vector

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

Published

16 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version with the fix for F2FS\_IOC\_MOVE\_RANGE validation.

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-2026-89840](https://nvd.nist.gov/vuln/detail/CVE-2026-89840)
- [https://git.kernel.org/stable/c/dcae1eeda53149f219dd6af93b3083b7271c1c63](https://git.kernel.org/stable/c/dcae1eeda53149f219dd6af93b3083b7271c1c63)
- [https://git.kernel.org/stable/c/e533889fc26aea0cd83c90327063f272061dd820](https://git.kernel.org/stable/c/e533889fc26aea0cd83c90327063f272061dd820)
- [https://git.kernel.org/stable/c/db13064669526494cd78ba3a4394063b740e940c](https://git.kernel.org/stable/c/db13064669526494cd78ba3a4394063b740e940c)
- [https://git.kernel.org/stable/c/bca61ee5192ea47003722486ae9588a2a4bb47b6](https://git.kernel.org/stable/c/bca61ee5192ea47003722486ae9588a2a4bb47b6)

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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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