CVE-2026-74530

Received Received - Intake

Bluetooth UAF Fix in Linux Kernel Bluetooth Stack

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback There is theoretical UAF if the conn is freed while the hci_sync task is running. Hold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to match the previous behavior.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-15

Last Modified

2026-08-17

Generated

2026-09-04

AI Q&A

2026-08-15

EPSS Evaluated

2026-09-03

NVD

CVE-2026-74530

EUVD

EUVD-2026-59723

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This is a use-after-free (UAF) vulnerability in the Linux kernel's Bluetooth subsystem. It occurs in the hci_sync component when the hci_connect_big_sync() callback runs. If a connection object (conn) is freed while this task is executing, it could lead to memory corruption or crashes.

Detection Guidance

This vulnerability is specific to the Linux kernel's Bluetooth subsystem and involves a potential use-after-free (UAF) condition in the hci_sync task. Detection requires checking kernel logs for Bluetooth-related errors or crashes, particularly during BIG (Broadcast Isochronous Group) synchronization operations.

Impact Analysis

This vulnerability could cause system instability, crashes, or potential privilege escalation if exploited. It specifically affects systems using Bluetooth functionality in the Linux kernel.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards as it is a low-level Linux kernel Bluetooth issue with no documented impact on data protection or privacy controls.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the Bluetooth hci_sync UAF vulnerability. Monitor kernel security advisories for updates.

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