---
id: CVE-2026-23396
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  wifi: mac80211: fix NULL deref in mesh_matches_local()

  mesh_matches_local() unconditionally dereferences ie->mesh_config to
  compare mesh configuration parameters
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  wifi: mac80211: fix NULL deref in mesh_matches_local()

  mesh_matches_local() unconditionally dereferences ie->mesh_config to
  compare mesh configuration parameters. When…
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-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 2.6.26.1, < 5.10.253'
  - 'linux_kernel >= 5.11, < 5.15.203'
  - 'linux_kernel >= 5.16, < 6.1.167'
  - 'linux_kernel >= 6.2, < 6.6.130'
  - 'linux_kernel >= 6.7, < 6.12.78'
  - 'linux_kernel >= 6.13, < 6.18.20'
  - 'linux_kernel >= 6.19, < 6.19.10'
  - linux_kernel = 2.6.26
  - linux_kernel = 7.0
patched:
  - linux_kernel 6.19.10
published: '2026-03-26'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:18:54.783'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-23396'
references:
  - url: 'https://git.kernel.org/stable/c/0a4da176ae4b4e075a19c00d3e269cfd5e05a813'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/14a4fd13657a3f2489db6566f081adfb27a49c64'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/44699c6cdfce80a0f296b54ae9314461e3e41b3d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/74de6fa472b03bc8cde0a081484e9960bcbda568'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7c55a3deaf7eaaafa2546f8de7fed19382a0a116'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a90279e7f7ea0b7e923a1c5ebee9a6b78b6d1004'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c1e3f2416fb27c816ce96d747d3e784e31f4d95c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c73bb9a2d33bf81f6eecaa0f474b6c6dbe9855bd'
    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: 0.00114
epssPercentile: 0.01393
ingestedAt: '2026-10-15T03:30:12.848Z'
---

## Overview

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

wifi: mac80211: fix NULL deref in mesh_matches_local()

mesh_matches_local() unconditionally dereferences ie->mesh_config to
compare mesh configuration parameters. When called from
mesh_rx_csa_frame(), the parsed action-frame elements may not contain a
Mesh Configuration IE, leaving ie->mesh_config NULL and triggering a
kernel NULL pointer dereference.

The other two callers are already safe:
  - ieee80211_mesh_rx_bcn_presp() checks !elems->mesh_config before
    calling mesh_matches_local()
  - mesh_plink_get_event() is only reached through
    mesh_process_plink_frame(), which checks !elems->mesh_config, too

mesh_rx_csa_frame() is the only caller that passes raw parsed elements
to mesh_matches_local() without guarding mesh_config. An adjacent
attacker can exploit this by sending a crafted CSA action frame that
includes a valid Mesh ID IE but omits the Mesh Configuration IE,
crashing the kernel.

The captured crash log:

Oops: general protection fault, probably for non-canonical address ...
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
Workqueue: events_unbound cfg80211_wiphy_work
[...]
Call Trace:
 <TASK>
 ? __pfx_mesh_matches_local (net/mac80211/mesh.c:65)
 ieee80211_mesh_rx_queued_mgmt (net/mac80211/mesh.c:1686)
 [...]
 ieee80211_iface_work (net/mac80211/iface.c:1754 net/mac80211/iface.c:1802)
 [...]
 cfg80211_wiphy_work (net/wireless/core.c:426)
 process_one_work (net/kernel/workqueue.c:3280)
 ? assign_work (net/kernel/workqueue.c:1219)
 worker_thread (net/kernel/workqueue.c:3352)
 ? __pfx_worker_thread (net/kernel/workqueue.c:3385)
 kthread (net/kernel/kthread.c:436)
 [...]
 ret_from_fork_asm (net/arch/x86/entry/entry_64.S:255)
 </TASK>

This patch adds a NULL check for ie->mesh_config at the top of
mesh_matches_local() to return false early when the Mesh Configuration
IE is absent.

## Affected

- `linux_kernel >= 2.6.26.1, < 5.10.253`
- `linux_kernel >= 5.11, < 5.15.203`
- `linux_kernel >= 5.16, < 6.1.167`
- `linux_kernel >= 6.2, < 6.6.130`
- `linux_kernel >= 6.7, < 6.12.78`
- `linux_kernel >= 6.13, < 6.18.20`
- `linux_kernel >= 6.19, < 6.19.10`
- `linux_kernel = 2.6.26`
- `linux_kernel = 7.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.10`