---
id: CVE-2026-31674
title: 'netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check()

  Reject rt match rules whose addrnr exceeds IP6T_RT_HOPS.

  rt_mt6() expects addrnr to stay within the boun…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    af9b7e2b765966457f4ec23be5bd34a141f89574
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    29ea965a1353bc8303877422f79c8211e9ba9c55
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    ded71f5684df16fa645cca5bf4fe6b0cd8a46119
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    d8795fde1f78669a87c87ac29fceab2f104daa8c
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    a28ebf6f99de270d6338ccdc3b49f3e818f99b7b
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    9d3f027327c2fa265f7f85ead41294792c3296ed
  - Linux 2.6.12
published: '2026-04-25'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:48:03.642Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31674'
references:
  - url: 'https://git.kernel.org/stable/c/13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa'
  - url: 'https://git.kernel.org/stable/c/af9b7e2b765966457f4ec23be5bd34a141f89574'
  - url: 'https://git.kernel.org/stable/c/29ea965a1353bc8303877422f79c8211e9ba9c55'
  - url: 'https://git.kernel.org/stable/c/c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59'
  - url: 'https://git.kernel.org/stable/c/ded71f5684df16fa645cca5bf4fe6b0cd8a46119'
  - url: 'https://git.kernel.org/stable/c/d8795fde1f78669a87c87ac29fceab2f104daa8c'
  - url: 'https://git.kernel.org/stable/c/a28ebf6f99de270d6338ccdc3b49f3e818f99b7b'
  - url: 'https://git.kernel.org/stable/c/9d3f027327c2fa265f7f85ead41294792c3296ed'
tags:
  - cve.org
epss: 0.00174
epssPercentile: 0.06083
ingestedAt: '2026-09-08T15:33:26.989Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

netfilter: ip6t_rt: reject oversized addrnr in rt_mt6_check()

Reject rt match rules whose addrnr exceeds IP6T_RT_HOPS.

rt_mt6() expects addrnr to stay within the bounds of rtinfo->addrs[].
Validate addrnr during rule installation so malformed rules are rejected
before the match logic can use an out-of-range value.

## Affected

- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 13e3e30ed3b5b67cc1db2bd58a5d09b0f07debfa`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < af9b7e2b765966457f4ec23be5bd34a141f89574`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 29ea965a1353bc8303877422f79c8211e9ba9c55`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < c6a503a9f4debc654e3a6a7ca1f7fce6a9953c59`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < ded71f5684df16fa645cca5bf4fe6b0cd8a46119`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < d8795fde1f78669a87c87ac29fceab2f104daa8c`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a28ebf6f99de270d6338ccdc3b49f3e818f99b7b`
- `Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9d3f027327c2fa265f7f85ead41294792c3296ed`
- `Linux 2.6.12`

## Remediation

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