CVE-2026-74540

high

Description

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.

References

https://git.kernel.org/stable/c/fd4c1e301bdec60a40728ea37de531cbccda501a

https://git.kernel.org/stable/c/c4740e7f23ff9a8210198d8b4703259e21b9f69d

https://git.kernel.org/stable/c/8325eafb38c3dee5af329266393763693d17381b

https://git.kernel.org/stable/c/58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136

https://git.kernel.org/stable/c/522b730c62c53a1981604fd73524697fd347830d

https://git.kernel.org/stable/c/1818180fe12d6cec7a437bc59cde8efdf6b10250

https://git.kernel.org/stable/c/15d6c2367217a6a20b1abae9f38ded716bf620f1

https://git.kernel.org/stable/c/09f447accc2570751e7d17f0dc0788b40d3edade

Details

Source: Mitre, NVD

Published: 2026-08-15

Updated: 2026-08-19

Risk Information

CVSS v2

Base Score: 8.3

Vector: CVSS2#AV:A/AC:L/Au:N/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.8

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: High

EPSS

EPSS: 0.00168