---
id: CVE-2026-43085
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator

  When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send()
  appends an NLMSG_DONE te…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator

  When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send()
  appends an NLMSG_DONE te…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 2.6.23.1, < 5.10.258'
  - 'linux_kernel >= 5.11, < 5.15.209'
  - 'linux_kernel >= 5.16, < 6.1.175'
  - 'linux_kernel >= 6.2, < 6.6.136'
  - 'linux_kernel >= 6.7, < 6.12.83'
  - 'linux_kernel >= 6.13, < 6.18.24'
  - 'linux_kernel >= 6.19, < 6.19.14'
  - linux_kernel = 2.6.23
  - linux_kernel = 7.0
patched:
  - linux_kernel 6.19.14
published: '2026-05-06'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T09:18:02.693'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-43085'
references:
  - url: 'https://git.kernel.org/stable/c/15d209bccf9273b4a8b4e579ba0e92d065b6ec8c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1f3083aec8836213da441270cdb1ab612dd82cf4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/296f18e1c3a87c915a92ed27832d5040a22d1072'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/368c22aea490f6f50df831b4f9e3623787686c5b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/57cc509d82b46150a11dcecc8b25eaa177eda34d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9e2182865de781c41ab16b7985e9d26dcefea867'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d1399632ba255d2e02c757af5d9f5d9279ce168c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d552bcfca323d175664d7444989b04f55666978a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00166
epssPercentile: 0.05205
ingestedAt: '2026-09-08T13:33:23.548Z'
---

## Overview

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

netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator

When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send()
appends an NLMSG_DONE terminator with sizeof(struct nfgenmsg) payload via
nlmsg_put(), but never initializes the nfgenmsg bytes. The nlmsg_put()
helper only zeroes alignment padding after the payload, not the payload
itself, so four bytes of stale kernel heap data are leaked to userspace
in the NLMSG_DONE message body.

Use nfnl_msg_put() to build the NLMSG_DONE terminator, which initializes
the nfgenmsg payload via nfnl_fill_hdr(), consistent with how
__build_packet_message() already constructs NFULNL_MSG_PACKET headers.

## Affected

- `linux_kernel >= 2.6.23.1, < 5.10.258`
- `linux_kernel >= 5.11, < 5.15.209`
- `linux_kernel >= 5.16, < 6.1.175`
- `linux_kernel >= 6.2, < 6.6.136`
- `linux_kernel >= 6.7, < 6.12.83`
- `linux_kernel >= 6.13, < 6.18.24`
- `linux_kernel >= 6.19, < 6.19.14`
- `linux_kernel = 2.6.23`
- `linux_kernel = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.14`