---
id: CVE-2026-43089
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  xfrm_user: fix info leak in build_mapping()

  struct xfrm_usersa_id has a one-byte padding hole after the proto
  field, which ends up never getting set to zero before cop…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  xfrm_user: fix info leak in build_mapping()

  struct xfrm_usersa_id has a one-byte padding hole after the proto
  field, which ends up never getting set to zero before cop…
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-401
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 2.6.29.1, < 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 = 7.0
patched:
  - linux_kernel 6.19.14
published: '2026-05-06'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T09:18:03.447'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-43089'
references:
  - url: 'https://git.kernel.org/stable/c/1beb76b2053b68c491b78370794b8ff63c8f8c02'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/521385cbd50ca9474396d88462fcdfa6489685d9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5a1a4b049ddde41466ccac0daeec326254b133f2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/700c9622b23c33b5933e6dcea816492c064e4e10'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/72a8de41c3eb4dcf22bf3b674ea38fb2f75d6f32'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c2779ae9a3e5a044e5ccd564681511bbbcc5fc0f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d3125c541a96fb3c0fc7210112684baf22b6c24d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f779a6b6cdb6e12baa0663063ac59ab2a8f20c0c'
    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: 0.00129
epssPercentile: 0.02853
ingestedAt: '2026-09-08T13:33:23.877Z'
---

## Overview

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

xfrm_user: fix info leak in build_mapping()

struct xfrm_usersa_id has a one-byte padding hole after the proto
field, which ends up never getting set to zero before copying out to
userspace.  Fix that up by zeroing out the whole structure before
setting individual variables.

## Affected

- `linux_kernel >= 2.6.29.1, < 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 = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.14`