CVE-2026-74540

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.

CVSS v3 8.8 HIGH

8.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 5.9

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/09f447accc2570751e7d17f0dc0788b40d3edade
https://git.kernel.org/stable/c/15d6c2367217a6a20b1abae9f38ded716bf620f1
https://git.kernel.org/stable/c/1818180fe12d6cec7a437bc59cde8efdf6b10250
https://git.kernel.org/stable/c/522b730c62c53a1981604fd73524697fd347830d
https://git.kernel.org/stable/c/58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136
https://git.kernel.org/stable/c/8325eafb38c3dee5af329266393763693d17381b
https://git.kernel.org/stable/c/c4740e7f23ff9a8210198d8b4703259e21b9f69d
https://git.kernel.org/stable/c/fd4c1e301bdec60a40728ea37de531cbccda501a

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-15 13:17

Updated : 2026-08-19 17:21

NVD link : CVE-2026-74540

Mitre link : CVE-2026-74540

CVE.ORG link : CVE-2026-74540

JSON object : View

Products Affected

No product.

CWE

No CWE.

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counterpart l2cap_connect_rsp() and the sibling handler\nl2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()\nto safely hold a reference, but l2cap_le_connect_rsp() was left\nunprotected.\n\nFix by adding l2cap_chan_hold_unless_zero() after the ident lookup\nand l2cap_chan_put() on the exit path, consistent with other L2CAP\nresponse handlers."}], "lastModified": "2026-08-19T17:21:09.300", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}