---
id: CVE-2026-31659
title: 'batman-adv: reject oversized global TT response buffers'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  batman-adv: reject oversized global TT response buffers

  batadv_tt_prepare_tvlv_global_data() builds the allocation length for a
  global TT response in 16-bit temporarie…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    7e5d007e0df946bffb8542fb112e0044014a5897
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    2997f4bd1f982e7013709946e00be89b507693fa
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    95c71365a2222908441b54d6f2c315e0c79fcec3
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    69d61639bc7e963c3b645e570279d731e7c89062
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    f970646b9a39539d1bac86822ac78b5915455ea9
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    de6c1dc3c7d01a152607e6fcecee4d5288283f10
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    cf2199171ef799ca7270019125f4a91bd20ad4d9
  - >-
    Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b <
    3a359bf5c61d52e7f09754108309d637532164a6
  - Linux 3.13
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T15:11:40.590672Z'
published: '2026-04-24'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:20:20.140Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-31659'
references:
  - url: 'https://git.kernel.org/stable/c/7e5d007e0df946bffb8542fb112e0044014a5897'
  - url: 'https://git.kernel.org/stable/c/2997f4bd1f982e7013709946e00be89b507693fa'
  - url: 'https://git.kernel.org/stable/c/95c71365a2222908441b54d6f2c315e0c79fcec3'
  - url: 'https://git.kernel.org/stable/c/69d61639bc7e963c3b645e570279d731e7c89062'
  - url: 'https://git.kernel.org/stable/c/f970646b9a39539d1bac86822ac78b5915455ea9'
  - url: 'https://git.kernel.org/stable/c/de6c1dc3c7d01a152607e6fcecee4d5288283f10'
  - url: 'https://git.kernel.org/stable/c/cf2199171ef799ca7270019125f4a91bd20ad4d9'
  - url: 'https://git.kernel.org/stable/c/3a359bf5c61d52e7f09754108309d637532164a6'
tags:
  - cve.org
epss: 0.00421
epssPercentile: 0.34949
ingestedAt: '2026-10-16T17:24:46.667Z'
---

## Overview

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

batman-adv: reject oversized global TT response buffers

batadv_tt_prepare_tvlv_global_data() builds the allocation length for a
global TT response in 16-bit temporaries. When a remote originator
advertises a large enough global TT, the TT payload length plus the VLAN
header offset can exceed 65535 and wrap before kmalloc().

The full-table response path still uses the original TT payload length when
it fills tt_change, so the wrapped allocation is too small and
batadv_tt_prepare_tvlv_global_data() writes past the end of the heap object
before the later packet-size check runs.

Fix this by rejecting TT responses whose TVLV value length cannot fit in
the 16-bit TVLV payload length field.

## Affected

- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < 7e5d007e0df946bffb8542fb112e0044014a5897`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < 2997f4bd1f982e7013709946e00be89b507693fa`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < 95c71365a2222908441b54d6f2c315e0c79fcec3`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < 69d61639bc7e963c3b645e570279d731e7c89062`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < f970646b9a39539d1bac86822ac78b5915455ea9`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < de6c1dc3c7d01a152607e6fcecee4d5288283f10`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < cf2199171ef799ca7270019125f4a91bd20ad4d9`
- `Linux >= 7ea7b4a142758deaf46c1af0ca9ceca6dd55138b < 3a359bf5c61d52e7f09754108309d637532164a6`
- `Linux 3.13`

## Remediation

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