CVE-2026-63948
Received Received - Intake

Bluetooth L2CAP Channel Reference Leak in Linux Kernel

Publication date: 2026-07-19

Last updated on: 2026-07-19

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix chan ref leak in l2cap_chan_timeout() on !conn __set_chan_timer() takes a l2cap_chan reference via l2cap_chan_hold() before scheduling the delayed work. The normal path in l2cap_chan_timeout() drops this reference with l2cap_chan_put() at the end, but the early return when chan->conn is NULL skips the put, leaking the reference. Add the missing l2cap_chan_put() before the early return.

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Meta Information

Published
2026-07-19
Last Modified
2026-07-19
Generated
2026-07-20
AI Q&A
2026-07-19
EPSS Evaluated
N/A
NVD
CVE-2026-63948
EUVD
EUVD-2026-45721

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This is a reference leak vulnerability in the Linux kernel's Bluetooth L2CAP implementation. The issue occurs in the l2cap_chan_timeout() function where a reference to a l2cap_chan object is acquired via l2cap_chan_hold() but not properly released when chan->conn is NULL. This leads to a memory leak as the reference count is not decremented.

Detection Guidance

This vulnerability is specific to the Linux kernel's Bluetooth L2CAP implementation and does not have direct network detection methods. You can check your kernel version and Bluetooth stack for affected configurations using commands like 'uname -a' and 'modinfo bluetooth'.

Impact Analysis

This vulnerability could lead to memory exhaustion over time as leaked references accumulate. This may cause system instability, crashes, or degraded performance, particularly in systems with heavy Bluetooth usage.

Compliance Impact

This vulnerability is a reference leak in the Linux kernel's Bluetooth L2CAP implementation. It does not directly impact data confidentiality, integrity, or availability in a way that would typically affect GDPR or HIPAA compliance. The issue is localized to resource management and could lead to system instability if left unpatched, but it does not involve unauthorized data access or processing.

Mitigation Strategies

Apply the latest kernel updates from your Linux distribution to patch the vulnerability. Restart services or reboot the system after applying updates to ensure the patched kernel is active.

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