---
title: "CVE-2026-89665: Linux Kernel - Improper Input Validation"
description: "Linux kernel contains a vulnerability in NFSv2 SETATTR/CREATE where out-of-range useconds values cause time value corruption due to integer overflow in sattr decoder, letting remote attackers cause improper time attribute handling, exploit requires crafted NFSv2 requests."
url: https://panop.io/threat-heartbeat/CVE-2026-89665/
---

# CVE-2026-89665 Linux Kernel - Improper Input Validation

Linux kernel contains a vulnerability in NFSv2 SETATTR/CREATE where out-of-range useconds values cause time value corruption due to integer overflow in sattr decoder, letting remote attackers cause improper time attribute handling, exploit requires crafted NFSv2 requests.

CVSS base score 8.2 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.62% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-89665)

## Details

Type

Improper Input Validation

Impact

Denial Of Service

CVSS vector

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

Published

11 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for NFSv2 useconds 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-2026-89665](https://nvd.nist.gov/vuln/detail/CVE-2026-89665)
- [https://git.kernel.org/stable/c/a937dd1aa2d92291fe0a1860d17e90d8f206cd22](https://git.kernel.org/stable/c/a937dd1aa2d92291fe0a1860d17e90d8f206cd22)
- [https://git.kernel.org/stable/c/ad02d095439f89cbd6629420c7e3ba476457b83b](https://git.kernel.org/stable/c/ad02d095439f89cbd6629420c7e3ba476457b83b)
- [https://git.kernel.org/stable/c/09a79d9ab35a39603c834e8f6333603292f9c816](https://git.kernel.org/stable/c/09a79d9ab35a39603c834e8f6333603292f9c816)
- [https://git.kernel.org/stable/c/1db456ffc22e045f49f7b9e62415a26b3f33f200](https://git.kernel.org/stable/c/1db456ffc22e045f49f7b9e62415a26b3f33f200)
- [https://git.kernel.org/stable/c/5296a2442d12d45d6eea7b4d3ec3ffecc1821cac](https://git.kernel.org/stable/c/5296a2442d12d45d6eea7b4d3ec3ffecc1821cac)
- [https://git.kernel.org/stable/c/cdc3299f7072777b09c9582a3b8b65bb163ddcf3](https://git.kernel.org/stable/c/cdc3299f7072777b09c9582a3b8b65bb163ddcf3)
- [https://git.kernel.org/stable/c/1195483965a5f63d2dde18054ec7e50a23b9071c](https://git.kernel.org/stable/c/1195483965a5f63d2dde18054ec7e50a23b9071c)
- [https://git.kernel.org/stable/c/26709c8ffe73772eb69e68d553ac71d91228dccc](https://git.kernel.org/stable/c/26709c8ffe73772eb69e68d553ac71d91228dccc)

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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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