CVE-2026-64406

Analyzed Analyzed - Analysis Complete

Use-After-Free in Linux Kernel Bluetooth Stack

Publication date: 2026-07-25

Last updated on: 2026-09-04

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: fix UAF in bt_accept_dequeue() bt_accept_get() takes a temporary reference before dropping the accept queue lock. bt_accept_dequeue() currently drops that reference before bt_accept_unlink(), leaving only the queue reference. bt_accept_unlink() drops the queue reference. The subsequent sock_hold() therefore accesses freed memory if it was the final reference, as observed by KASAN during listening L2CAP socket cleanup. Retain the temporary queue-walk reference through unlink and hand it to the caller on success. Drop it explicitly on the closed and not-yet-connected paths.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-07-25

Last Modified

2026-09-04

Generated

2026-09-23

AI Q&A

2026-07-25

EPSS Evaluated

2026-09-22

NVD

CVE-2026-64406

EUVD

EUVD-2026-48950

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	7.1
linux	linux_kernel	From 5.15.210 (inc) to 5.15.212 (exc)
linux	linux_kernel	7.2
linux	linux_kernel	7.2
linux	linux_kernel	From 6.1.175 (inc) to 6.1.178 (exc)
linux	linux_kernel	From 6.6.142 (inc) to 6.6.145 (exc)
linux	linux_kernel	From 7.0.11 (inc) to 7.1 (exc)
linux	linux_kernel	7.1
linux	linux_kernel	From 6.12.92 (inc) to 6.12.96 (exc)
linux	linux_kernel	From 6.18.34 (inc) to 6.18.39 (exc)
linux	linux_kernel	From 5.10.259 (inc) to 5.10.261 (exc)
linux	linux_kernel	From 7.1.1 (inc) to 7.1.4 (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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 is a use-after-free (UAF) vulnerability in the Linux kernel's Bluetooth subsystem. It occurs in the bt_accept_dequeue() function where a temporary reference is dropped too early, leading to accessing freed memory during L2CAP socket cleanup. The issue arises when the final reference is dropped before the sock_hold() operation, which can cause memory corruption.

Detection Guidance

This vulnerability is specific to the Linux kernel's Bluetooth subsystem and may not have direct detection commands. Monitor kernel logs for Bluetooth-related crashes or KASAN reports indicating use-after-free in bt_accept_dequeue. Check for kernel oops or panics related to Bluetooth operations.

Impact Analysis

This vulnerability could allow an attacker to cause a denial-of-service (system crash) or potentially execute arbitrary code with kernel privileges. It affects systems using Bluetooth with L2CAP sockets, potentially leading to system instability or unauthorized access.

Compliance Impact

This vulnerability is a use-after-free (UAF) issue in the Linux kernel's Bluetooth subsystem. It does not directly impact compliance with standards like GDPR or HIPAA, as those focus on data protection and privacy controls rather than kernel memory management flaws.

Mitigation Strategies

Update the Linux kernel to the latest stable version that includes the fix for this vulnerability. If immediate patching is not possible, disable Bluetooth functionality temporarily to reduce exposure until the kernel is updated.

Hi! I’m here to help you understand CVE-2026-64406. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70