CVE-2026-43018

Analyzed Analyzed - Analysis Complete

Use-After-Free in Linux Kernel Bluetooth Subsystem

Publication date: 2026-05-01

Last updated on: 2026-05-08

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_event: fix potential UAF in hci_le_remote_conn_param_req_evt hci_conn lookup and field access must be covered by hdev lock in hci_le_remote_conn_param_req_evt, otherwise it's possible it is freed concurrently. Extend the hci_dev_lock critical section to cover all conn usage.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-05-01

Last Modified

2026-05-08

Generated

2026-07-06

AI Q&A

2026-05-01

EPSS Evaluated

2026-07-05

NVD

CVE-2026-43018

EUVD

EUVD-2026-26617

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	From 6.13 (inc) to 6.18.22 (exc)
linux	linux_kernel	From 5.17 (inc) to 6.1.168 (exc)
linux	linux_kernel	From 6.19 (inc) to 6.19.12 (exc)
linux	linux_kernel	From 6.7 (inc) to 6.12.81 (exc)
linux	linux_kernel	From 6.2 (inc) to 6.6.134 (exc)

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 vulnerability exists in the Linux kernel's Bluetooth subsystem, specifically in the handling of the hci_le_remote_conn_param_req_evt event.

The issue is a potential Use-After-Free (UAF) condition caused by accessing a connection object (hci_conn) without proper locking (hdev lock). If the connection object is freed concurrently while being accessed, it can lead to undefined behavior or crashes.

The fix involves extending the critical section protected by the hci_dev_lock to cover all usage of the connection object, ensuring it cannot be freed while in use.

Impact Analysis

Exploitation of this vulnerability could lead to instability or crashes in the Bluetooth subsystem of the Linux kernel.

A Use-After-Free condition might be leveraged by an attacker to execute arbitrary code, cause denial of service, or trigger other unexpected behavior depending on the context.

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