CVE-2026-68393

Received Received - Intake

Bluetooth Use-After-Free in Linux Kernel

Publication date: 2026-08-10

Last updated on: 2026-10-21

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: extend conn_hash lookup critical sections Using RCU-protected pointers outside the critical sections without refcount is incorrect and may result to UAF. Extend critical section to cover both hci_conn_hash lookup and use of the returned conn. Add surrounding rcu_read_lock() also when return value is not used, in preparation for RCU lockdep requirement to hci_lookup_le_connect(). This avoids concurrent deletion of the conn before we are done dereferencing it. Also, make sure to hold hdev->lock when accessing hdev->accept_list.

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Meta Information

Published

2026-08-10

Last Modified

2026-10-21

Generated

2026-11-08

AI Q&A

2026-08-10

EPSS Evaluated

2026-11-07

NVD

CVE-2026-68393

EUVD

EUVD-2026-55579

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This is a Linux kernel Bluetooth vulnerability where RCU-protected pointers are used outside critical sections without proper reference counting, potentially leading to a use-after-free (UAF) condition. The fix extends critical sections to cover both the lookup and use of the connection hash, ensuring the connection isn't deleted concurrently while being accessed.

Detection Guidance

This vulnerability is specific to the Linux kernel's Bluetooth subsystem and requires kernel-level inspection. Detection involves checking kernel logs for Bluetooth-related errors or crashes, particularly around hci_sync or hci_conn_hash operations. Commands like dmesg | grep -i bluetooth or journalctl -k | grep -i bluetooth may help identify issues. Kernel version checks (uname -r) can confirm if your system is affected if the version predates the fix.

Impact Analysis

An attacker within Bluetooth range could exploit this to cause a system crash or execute arbitrary code with kernel privileges, leading to denial of service or unauthorized access to sensitive data on affected systems.

Compliance Impact

This vulnerability could lead to unauthorized data access or system compromise, violating GDPR's integrity and confidentiality requirements or HIPAA's security controls for protected health information. Compliance may be impacted if exploited.

Mitigation Strategies

Immediate mitigation involves updating the Linux kernel to a patched version that includes the fix for this vulnerability. Check your distribution's security updates or kernel patches. If updating is not immediately possible, consider disabling Bluetooth functionality temporarily until the patch is applied.

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