---
id: CVE-2026-43035
title: >-
  In the Linux kernel, the following vulnerability has been resolved:


  net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to
  prevent an info-leak


  When building netlink messages, tc_chain_fill_node() never initializ…
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to
  prevent an info-leak


  When building netlink messages, tc_chain_fill_node() never initializ…
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'
cwe:
  - CWE-908
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 4.19, < 5.10.253'
  - 'linux_kernel >= 5.11, < 5.15.203'
  - 'linux_kernel >= 5.16, < 6.1.168'
  - 'linux_kernel >= 6.2, < 6.6.134'
  - 'linux_kernel >= 6.7, < 6.12.81'
  - 'linux_kernel >= 6.13, < 6.18.22'
  - 'linux_kernel >= 6.19, < 6.19.12'
  - linux_kernel = 7.0
patched:
  - linux_kernel 6.19.12
published: '2026-05-01'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:19:27.433'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-43035'
references:
  - url: 'https://git.kernel.org/stable/c/1091b3c174441a52fdbb92e2fe00338f9371a91c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4ae5d23f51fb91d7d1140c6f1ba77ab0756054c3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/71a3eda7e850ae844cb8993065f4e410c11a46ce'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/903c3405cfcc7700260e456ab66a5867586c9e69'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/906997ea3766c24fbbf9cc4bf17c047315bbd138'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d6db08484c6cb3d4ad696246f9d288eceba2a078'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e35f5195cd44ff4053fbc5d71ea97681728a0099'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e6e3eb5ee89ac4c163d46429391c889a1bb5e404'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-457936.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00129
epssPercentile: 0.025
ingestedAt: '2026-09-08T15:33:26.989Z'
---

## Overview

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

net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak

When building netlink messages, tc_chain_fill_node() never initializes
the tcm_info field of struct tcmsg. Since the allocation is not zeroed,
kernel heap memory is leaked to userspace through this 4-byte field.

The fix simply zeroes tcm_info alongside the other fields that are
already initialized.

## Affected

- `linux_kernel >= 4.19, < 5.10.253`
- `linux_kernel >= 5.11, < 5.15.203`
- `linux_kernel >= 5.16, < 6.1.168`
- `linux_kernel >= 6.2, < 6.6.134`
- `linux_kernel >= 6.7, < 6.12.81`
- `linux_kernel >= 6.13, < 6.18.22`
- `linux_kernel >= 6.19, < 6.19.12`
- `linux_kernel = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.12`