What’s Vulnerable › Vulnerabilities

CVE-2026-74540: Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-15 · updated 2026-10-16

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.

Affected products

• Linux kernel: 3.14 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

• 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

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