---
id: CVE-2026-31738
title: 'vxlan: validate ND option lengths in vxlan_na_create'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  vxlan: validate ND option lengths in vxlan_na_create

  vxlan_na_create() walks ND options according to option-provided
  lengths. A malformed option can make the parser ad…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    901c1dd3bab2955d7e664f914c374c8c3ac2b958
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    e476745917a1e288eb15e7ff49d286a86a4861d3
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    2029712fb2c87e9a8c75094906f2ee29bf08c500
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    602596c69a70e50d9ab8c6ae0290a01f88229dd7
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    de20d2e3b9179d132f5f5b44e490d7c916c6321b
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    eddfce70a6f3107d1679b0c2fcbeb96b593bd679
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    b69c4236255bd8de16cd876e58c6f0867d1d78b1
  - >-
    Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa <
    afa9a05e6c4971bd5586f1b304e14d61fb3d9385
  - Linux d8be18c52dbc94989f6d74637b731af39cd3d902
  - Linux 3927dace523706cc00f808520eaf2125dd7c07b5
  - Linux >= 3.12.18 < 3.13
  - Linux >= 3.13.10 < 3.14
  - Linux 3.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T15:24:44.664769Z'
published: '2026-05-01'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T15:32:23.909Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31738'
references:
  - url: 'https://git.kernel.org/stable/c/901c1dd3bab2955d7e664f914c374c8c3ac2b958'
  - url: 'https://git.kernel.org/stable/c/e476745917a1e288eb15e7ff49d286a86a4861d3'
  - url: 'https://git.kernel.org/stable/c/2029712fb2c87e9a8c75094906f2ee29bf08c500'
  - url: 'https://git.kernel.org/stable/c/602596c69a70e50d9ab8c6ae0290a01f88229dd7'
  - url: 'https://git.kernel.org/stable/c/de20d2e3b9179d132f5f5b44e490d7c916c6321b'
  - url: 'https://git.kernel.org/stable/c/eddfce70a6f3107d1679b0c2fcbeb96b593bd679'
  - url: 'https://git.kernel.org/stable/c/b69c4236255bd8de16cd876e58c6f0867d1d78b1'
  - url: 'https://git.kernel.org/stable/c/afa9a05e6c4971bd5586f1b304e14d61fb3d9385'
tags:
  - cve.org
epss: 0.00123
epssPercentile: 0.02053
ingestedAt: '2026-11-06T15:54:04.042Z'
---

## Overview

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

vxlan: validate ND option lengths in vxlan_na_create

vxlan_na_create() walks ND options according to option-provided
lengths. A malformed option can make the parser advance beyond the
computed option span or use a too-short source LLADDR option payload.

Validate option lengths against the remaining NS option area before
advancing, and only read source LLADDR when the option is large enough
for an Ethernet address.

## Affected

- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < 901c1dd3bab2955d7e664f914c374c8c3ac2b958`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < e476745917a1e288eb15e7ff49d286a86a4861d3`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < 2029712fb2c87e9a8c75094906f2ee29bf08c500`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < 602596c69a70e50d9ab8c6ae0290a01f88229dd7`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < de20d2e3b9179d132f5f5b44e490d7c916c6321b`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < eddfce70a6f3107d1679b0c2fcbeb96b593bd679`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < b69c4236255bd8de16cd876e58c6f0867d1d78b1`
- `Linux >= 4b29dba9c085a4fb79058fb1c45a2f6257ca3dfa < afa9a05e6c4971bd5586f1b304e14d61fb3d9385`
- `Linux d8be18c52dbc94989f6d74637b731af39cd3d902`
- `Linux 3927dace523706cc00f808520eaf2125dd7c07b5`
- `Linux >= 3.12.18 < 3.13`
- `Linux >= 3.13.10 < 3.14`
- `Linux 3.14`

## Remediation

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