---
id: CVE-2026-52909
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ip6_vti: set netns_immutable on the fallback device.

  john1988 and Noam Rathaus reported that vti6_init_net() does not set the
  netns_immutable flag on the per-netns fal…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ip6_vti: set netns_immutable on the fallback device.

  john1988 and Noam Rathaus reported that vti6_init_net() does not set the
  netns_immutable flag on the per-netns fal…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.15, < 5.10.260'
  - 'linux_kernel >= 5.11, < 5.15.211'
  - 'linux_kernel >= 5.16, < 6.1.177'
  - 'linux_kernel >= 6.2, < 6.6.144'
  - 'linux_kernel >= 6.7, < 6.12.95'
  - 'linux_kernel >= 6.13, < 6.18.36'
  - 'linux_kernel >= 6.19, < 7.0.13'
  - linux_kernel = 7.1
patched:
  - linux_kernel 7.0.13
published: '2026-06-19'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:19:55.577'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52909'
references:
  - url: 'https://git.kernel.org/stable/c/12acc977838c943636fb01e2f3087d2e4cc3b7cc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/12c65e2c7fef507551bd7b52123598a761662c01'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7f28e3948c59481f8db9c9638e204258d26b4e41'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c5dbd669db5a426b3025512322e1bf2cdbe14305'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d289d5307762d1838aaece22c6b6fcad9e8865f9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/dcdce3bc9f08026ff3739ee7339e1bef526fc5f3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ecf8904067dcba0dad86ece80874841e60317885'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f4b6b4af7ef0661ac153c6f7eb1030aa8482c1a3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-784472.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00113
epssPercentile: 0.01431
ingestedAt: '2026-07-04T12:56:09.602Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:22:25.382574Z'
---

## Overview

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

ip6_vti: set netns_immutable on the fallback device.

john1988 and Noam Rathaus reported that vti6_init_net() does not set the
netns_immutable flag on the per-netns fallback tunnel device (ip6_vti0).

Other similar tunnel drivers (like ip6_tunnel, sit, ip6_gre, and ip_tunnel)
correctly set this flag during their fallback device initialization to
prevent them from being moved to another network namespace.

## Affected

- `linux_kernel >= 3.15, < 5.10.260`
- `linux_kernel >= 5.11, < 5.15.211`
- `linux_kernel >= 5.16, < 6.1.177`
- `linux_kernel >= 6.2, < 6.6.144`
- `linux_kernel >= 6.7, < 6.12.95`
- `linux_kernel >= 6.13, < 6.18.36`
- `linux_kernel >= 6.19, < 7.0.13`
- `linux_kernel = 7.1`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.0.13`