CVE-2026-53072
Received Received - Intake
Bluetooth Use-After-Free in Linux Kernel

Publication date: 2026-06-24

Last updated on: 2026-06-24

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER When protocol sets HCI_PROTO_DEFER, hci_conn_request_evt() calls hci_connect_cfm(conn) without hdev->lock. Generally hci_connect_cfm() assumes it is held, and if conn is deleted concurrently -> UAF. Only SCO and ISO set HCI_PROTO_DEFER and only for defer setup listen, and HCI_EV_CONN_REQUEST is not generated for ISO. In the non-deferred listening socket code paths, hci_connect_cfm(conn) is called with hdev->lock held. Fix by holding the lock.
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Meta Information
Published
2026-06-24
Last Modified
2026-06-24
Generated
2026-06-25
AI Q&A
2026-06-24
EPSS Evaluated
N/A
NVD
EUVD
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability exists in the Linux kernel's Bluetooth subsystem. Specifically, when the protocol sets HCI_PROTO_DEFER, the function hci_conn_request_evt() calls hci_connect_cfm(conn) without holding the hdev->lock. Normally, hci_connect_cfm() expects this lock to be held. If the connection (conn) is deleted concurrently during this call, it can lead to a use-after-free (UAF) condition.

Only SCO and ISO protocols set HCI_PROTO_DEFER, and HCI_EV_CONN_REQUEST is not generated for ISO. In other code paths where listening is not deferred, the lock is properly held when calling hci_connect_cfm(conn). The fix involves ensuring the lock is held during this call to prevent the UAF.

Impact Analysis

This vulnerability can lead to a use-after-free condition in the Bluetooth subsystem of the Linux kernel. Such a condition may cause system instability, crashes, or potentially allow an attacker to execute arbitrary code or escalate privileges if they can trigger the vulnerable code path.

Mitigation Strategies

The vulnerability has been fixed in the Linux kernel by ensuring proper locking in the Bluetooth hci_conn_request_evt() function. To mitigate this vulnerability, you should update your Linux kernel to a version that includes this fix.

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