CVE-2026-53276
Received Received - Intake
Bluetooth Use-After-Free in Linux Kernel

Publication date: 2026-06-25

Last updated on: 2026-06-25

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: Fix a use-after-free of the hci_conn pointer In iso_sock_rebind_bc(), the bis pointer is cached, then the socket lock is dropped: bis = iso_pi(sk)->conn->hcon; /* Release the socket before lookups since that requires hci_dev_lock * which shall not be acquired while holding sock_lock for proper * ordering. */ release_sock(sk); hci_dev_lock(bis->hdev); During the unlocked window, could a concurrent close() destroy the connection and free the bis structure, causing hci_dev_lock(bis->hdev) to access memory after it is freed, fix this by using the hdev reference which was safely acquired via iso_conn_get_hdev().
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Meta Information
Published
2026-06-25
Last Modified
2026-06-25
Generated
2026-06-25
AI Q&A
2026-06-25
EPSS Evaluated
N/A
NVD
CVE-2026-53276
EUVD
EUVD-2026-39227
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *
Helpful Resources
Exploitability
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KEV
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability is a use-after-free issue in the Linux kernel's Bluetooth ISO implementation. Specifically, in the function iso_sock_rebind_bc(), a pointer to a Bluetooth connection (hci_conn) is cached and then the socket lock is released. During this unlocked period, if a concurrent close() operation occurs, it can destroy the connection and free the memory that the pointer references. Subsequently, the code attempts to access this freed memory, leading to a use-after-free condition. The fix involves using a safely acquired reference to the Bluetooth device (hdev) to avoid accessing freed memory.

Mitigation Strategies

The vulnerability is resolved in the Linux kernel by fixing a use-after-free issue in the Bluetooth ISO code. To mitigate this vulnerability, you should update your Linux kernel to a version that includes this fix.

Impact Analysis

This use-after-free vulnerability can lead to undefined behavior such as system crashes, memory corruption, or potentially allow an attacker to execute arbitrary code within the kernel. Exploiting this flaw could compromise system stability and security, especially on devices using Bluetooth functionality in the Linux kernel.

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