---
title: "CVE-2026-90237: Linux Kernel netfilter nft_ct - Denial of Service"
description: "Linux kernel netfilter nft_ct contains a logic flaw in custom connection tracking expectation support caused by improper handling of confirmed and unconfirmed conntracks, letting attackers cause kernel crashes or stale state, exploit requires crafted network traffic."
url: https://panop.io/threat-heartbeat/CVE-2026-90237/
---

# CVE-2026-90237 Linux Kernel netfilter nft\_ct - Denial of Service

Linux kernel netfilter nft\_ct contains a logic flaw in custom connection tracking expectation support caused by improper handling of confirmed and unconfirmed conntracks, letting attackers cause kernel crashes or stale state, exploit requires crafted network traffic.

CVSS base score 7.8 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.17% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-90237)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

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

Published

17 September 2026

Updated

15 October 2026

## Vendor fix

Update to the latest Linux kernel version containing the fix for this issue.

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-2026-90237](https://nvd.nist.gov/vuln/detail/CVE-2026-90237)
- [https://git.kernel.org/stable/c/3679da4ad8be84cddaf40bc307fef1fe13e051ff](https://git.kernel.org/stable/c/3679da4ad8be84cddaf40bc307fef1fe13e051ff)
- [https://git.kernel.org/stable/c/af3fe52fd108fd38235e4813df62442ed0f1d8ff](https://git.kernel.org/stable/c/af3fe52fd108fd38235e4813df62442ed0f1d8ff)

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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

Panop answers these inside your environment, for this CVE and every other finding.

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