CVE-2026-74540
Last modified
CVE-2026-74540 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. 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.. EPSS estimates a 0.25% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < 15d6c2367217a6a20b1abae9f38ded716bf620f1; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < 1818180fe12d6cec7a437bc59cde8efdf6b10250; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < 8325eafb38c3dee5af329266393763693d17381b; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < fd4c1e301bdec60a40728ea37de531cbccda501a; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < 522b730c62c53a1981604fd73524697fd347830d; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < 58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < 09f447accc2570751e7d17f0dc0788b40d3edade; >= f1496dee9cbde2a62821f4441dadb0d3360f60c3, < c4740e7f23ff9a8210198d8b4703259e21b9f69d |
| Linux | Linux | 3.14 |
References
Timeline
- Published
- Last Modified
- Status
- Received
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