---
id: CVE-2022-2663
title: >-
  An issue was found in the Linux kernel in nf_conntrack_irc where the message
  handling can be confused and incorrectly matches the message
summary: >-
  An issue was found in the Linux kernel in nf_conntrack_irc where the message
  handling can be confused and incorrectly matches the message. A firewall may
  be able to be bypassed when users are using unencrypted IRC with
  nf_conntrack_irc c…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-923
vendor: linux
product: linux_kernel
affected:
  - linux_kernel
  - debian_linux = 10.0
  - debian_linux = 11.0
published: '2022-09-01'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T14:17:22.007'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-2663'
references:
  - url: 'https://dgl.cx/2022/08/nat-again-irc-cve-2022-2663'
    label: secalert@redhat.com
  - url: 'https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html'
    label: secalert@redhat.com
  - url: 'https://lists.debian.org/debian-lts-announce/2022/11/msg00001.html'
    label: secalert@redhat.com
  - url: >-
      https://lore.kernel.org/netfilter-devel/20220826045658.100360-1-dgl%40dgl.cx/T/
    label: secalert@redhat.com
  - url: 'https://www.debian.org/security/2022/dsa-5257'
    label: secalert@redhat.com
  - url: 'https://www.openwall.com/lists/oss-security/2022/08/30/1'
    label: secalert@redhat.com
  - url: 'https://www.youtube.com/watch?v=WIq-YgQuYCA'
    label: secalert@redhat.com
  - url: 'https://dgl.cx/2022/08/nat-again-irc-cve-2022-2663'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2022/11/msg00001.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://lore.kernel.org/netfilter-devel/20220826045658.100360-1-dgl%40dgl.cx/T/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2022/dsa-5257'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.openwall.com/lists/oss-security/2022/08/30/1'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.youtube.com/watch?v=WIq-YgQuYCA'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-769027.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-794697.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
epss: 0.03194
epssPercentile: 0.87799
ingestedAt: '2026-10-14T15:36:13.918Z'
---

## Overview

An issue was found in the Linux kernel in nf_conntrack_irc where the message handling can be confused and incorrectly matches the message. A firewall may be able to be bypassed when users are using unencrypted IRC with nf_conntrack_irc configured.

## Affected

- `linux_kernel`
- `debian_linux = 10.0`
- `debian_linux = 11.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.