---
id: CVE-2026-53249
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options

  This patch restricts setting Loose Source and Record Route (LSRR)
  and Strict Source and Record Route (SSRR) IP options…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options

  This patch restricts setting Loose Source and Record Route (LSRR)
  and Strict Source and Record Route (SSRR) IP options…
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 >= 2.6.12.1, < 5.10.259'
  - 'linux_kernel >= 5.11, < 5.15.210'
  - 'linux_kernel >= 5.16, < 6.1.176'
  - 'linux_kernel >= 6.2, < 6.6.143'
  - 'linux_kernel >= 6.7, < 6.12.94'
  - 'linux_kernel >= 6.13, < 6.18.36'
  - 'linux_kernel >= 6.19, < 7.0.13'
  - linux_kernel = 2.6.12
  - linux_kernel = 7.1
patched:
  - linux_kernel 7.0.13
published: '2026-06-25'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T09:18:15.233'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-53249'
references:
  - url: 'https://git.kernel.org/stable/c/00e8845fe3428c69e980dce5071cb3da1d8f7578'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/28f5ad1b4055405eb1616e603fe511ba5e3725e7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2a87c3e8f03ce655ed0ef500d64d5fd924ec3691'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4cd6e9ed49347d3a2fdaaf07e32fb524756dddc2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/89343ff12b3178fc236fe531a3603e7c97c68278'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8ff85dbabbbfb05e86e6cde31d91ac5782179d4d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a4f3fd6516920988c47ba8d19714985c40c816a1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d3915a1f5a4bc0ac911032903c3c6ab8df9fcc7c'
    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: 0.00125
epssPercentile: 0.01914
ingestedAt: '2026-09-08T15:33:26.945Z'
---

## Overview

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

ipv4: restrict IPOPT_SSRR and IPOPT_LSRR options

This patch restricts setting Loose Source and Record Route (LSRR)
and Strict Source and Record Route (SSRR) IP options to users
with CAP_NET_RAW capability.

This prevents unprivileged applications from forcing packets to route
through attacker-controlled nodes to leak TCP ISN and possibly other
protocol information.

While LSRR and SSRR are commonly filtered in many network environments,
they may still be supported and forwarded along some network paths.

RFC 7126 (Recommendations on Filtering of IPv4 Packets Containing
IPv4 Options) recommend to drop these options in 4.3 and 4.4.

## Affected

- `linux_kernel >= 2.6.12.1, < 5.10.259`
- `linux_kernel >= 5.11, < 5.15.210`
- `linux_kernel >= 5.16, < 6.1.176`
- `linux_kernel >= 6.2, < 6.6.143`
- `linux_kernel >= 6.7, < 6.12.94`
- `linux_kernel >= 6.13, < 6.18.36`
- `linux_kernel >= 6.19, < 7.0.13`
- `linux_kernel = 2.6.12`
- `linux_kernel = 7.1`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.13`