---
id: CVE-2026-74540
title: 'Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp

  l2cap_le_connect_rsp() obtains a channel via
  __l2cap_get_chan_by_ident() but neither holds a reference nor uses
  l2cap…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    15d6c2367217a6a20b1abae9f38ded716bf620f1
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    1818180fe12d6cec7a437bc59cde8efdf6b10250
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    8325eafb38c3dee5af329266393763693d17381b
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    fd4c1e301bdec60a40728ea37de531cbccda501a
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    522b730c62c53a1981604fd73524697fd347830d
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    09f447accc2570751e7d17f0dc0788b40d3edade
  - >-
    Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 <
    c4740e7f23ff9a8210198d8b4703259e21b9f69d
  - Linux 3.14
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:59:42.755795Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:05:54.604Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-74540'
references:
  - url: 'https://git.kernel.org/stable/c/15d6c2367217a6a20b1abae9f38ded716bf620f1'
  - url: 'https://git.kernel.org/stable/c/1818180fe12d6cec7a437bc59cde8efdf6b10250'
  - url: 'https://git.kernel.org/stable/c/8325eafb38c3dee5af329266393763693d17381b'
  - url: 'https://git.kernel.org/stable/c/fd4c1e301bdec60a40728ea37de531cbccda501a'
  - url: 'https://git.kernel.org/stable/c/522b730c62c53a1981604fd73524697fd347830d'
  - url: 'https://git.kernel.org/stable/c/58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136'
  - url: 'https://git.kernel.org/stable/c/09f447accc2570751e7d17f0dc0788b40d3edade'
  - url: 'https://git.kernel.org/stable/c/c4740e7f23ff9a8210198d8b4703259e21b9f69d'
tags:
  - cve.org
epss: 0.00255
epssPercentile: 0.15954
ingestedAt: '2026-10-16T19:46:24.344Z'
---

## Overview

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

Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp

l2cap_le_connect_rsp() obtains a channel via
__l2cap_get_chan_by_ident() but neither holds a reference nor uses
l2cap_chan_hold_unless_zero() before locking and operating on it.
A concurrent l2cap_chan_del() triggered by a remote disconnect can
free the channel between the lookup and l2cap_chan_lock(), causing
a use-after-free.

The BR/EDR counterpart l2cap_connect_rsp() and the sibling handler
l2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()
to safely hold a reference, but l2cap_le_connect_rsp() was left
unprotected.

Fix by adding l2cap_chan_hold_unless_zero() after the ident lookup
and l2cap_chan_put() on the exit path, consistent with other L2CAP
response handlers.

## Affected

- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 15d6c2367217a6a20b1abae9f38ded716bf620f1`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 1818180fe12d6cec7a437bc59cde8efdf6b10250`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 8325eafb38c3dee5af329266393763693d17381b`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < fd4c1e301bdec60a40728ea37de531cbccda501a`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 522b730c62c53a1981604fd73524697fd347830d`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 09f447accc2570751e7d17f0dc0788b40d3edade`
- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < c4740e7f23ff9a8210198d8b4703259e21b9f69d`
- `Linux 3.14`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.