---
id: CVE-2026-31682
title: 'bridge: br_nd_send: linearize skb before parsing ND options'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bridge: br_nd_send: linearize skb before parsing ND options

  br_nd_send() parses neighbour discovery options from ns->opt[] and
  assumes that these options are in the li…
severity: critical
cvss: 9.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    c68433fd291c9e88c00292095172c62d1997d662
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    4f397b950c916e9a1f8a4fce04ea0110206cad47
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    bd91ec85aa4c77d645bd2739fc56784157a88ca2
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    658261898130da620fc3d0fbb0523efb3366cb55
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    2ba4caba423ed94d63006eb1d2227b0332ab7fcd
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    9c55e41c73af5c4511070933b1bd25248521270c
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    3a30f6469b058574f49efde61cd6f5d79e576053
  - >-
    Linux >= ed842faeb2bd49256f00485402f3113205f91d30 <
    a01aee7cafc575bb82f5529e8734e7052f9b16ea
  - Linux 4.15
published: '2026-04-25'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:48:09.287Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31682'
references:
  - url: 'https://git.kernel.org/stable/c/c68433fd291c9e88c00292095172c62d1997d662'
  - url: 'https://git.kernel.org/stable/c/4f397b950c916e9a1f8a4fce04ea0110206cad47'
  - url: 'https://git.kernel.org/stable/c/bd91ec85aa4c77d645bd2739fc56784157a88ca2'
  - url: 'https://git.kernel.org/stable/c/658261898130da620fc3d0fbb0523efb3366cb55'
  - url: 'https://git.kernel.org/stable/c/2ba4caba423ed94d63006eb1d2227b0332ab7fcd'
  - url: 'https://git.kernel.org/stable/c/9c55e41c73af5c4511070933b1bd25248521270c'
  - url: 'https://git.kernel.org/stable/c/3a30f6469b058574f49efde61cd6f5d79e576053'
  - url: 'https://git.kernel.org/stable/c/a01aee7cafc575bb82f5529e8734e7052f9b16ea'
tags:
  - cve.org
epss: 0.00845
epssPercentile: 0.56221
ingestedAt: '2026-09-08T15:33:26.989Z'
---

## Overview

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

bridge: br_nd_send: linearize skb before parsing ND options

br_nd_send() parses neighbour discovery options from ns->opt[] and
assumes that these options are in the linear part of request.

Its callers only guarantee that the ICMPv6 header and target address
are available, so the option area can still be non-linear. Parsing
ns->opt[] in that case can access data past the linear buffer.

Linearize request before option parsing and derive ns from the linear
network header.

## Affected

- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < c68433fd291c9e88c00292095172c62d1997d662`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 4f397b950c916e9a1f8a4fce04ea0110206cad47`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < bd91ec85aa4c77d645bd2739fc56784157a88ca2`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 658261898130da620fc3d0fbb0523efb3366cb55`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 2ba4caba423ed94d63006eb1d2227b0332ab7fcd`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 9c55e41c73af5c4511070933b1bd25248521270c`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < 3a30f6469b058574f49efde61cd6f5d79e576053`
- `Linux >= ed842faeb2bd49256f00485402f3113205f91d30 < a01aee7cafc575bb82f5529e8734e7052f9b16ea`
- `Linux 4.15`

## Remediation

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