Linux Kernel up to 6.18.8 Bluetooth hci_uart_set_proto null pointer dereference

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5.0	$0-$5k	0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.18.8. Affected is the function hci_uart_set_proto of the component Bluetooth. The manipulation results in null pointer dereference. This vulnerability is identified as CVE-2026-23146. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.18.8. Affected is the function hci_uart_set_proto of the component Bluetooth. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_uart: fix null-ptr-deref in hci_uart_write_work hci_uart_set_proto() sets HCI_UART_PROTO_INIT before calling hci_uart_register_dev(), which calls proto->open() to initialize hu->priv. However, if a TTY write wakeup occurs during this window, hci_uart_tx_wakeup() may schedule write_work before hu->priv is initialized, leading to a NULL pointer dereference in hci_uart_write_work() when proto->dequeue() accesses hu->priv. The race condition is: CPU0 CPU1 ---- ---- hci_uart_set_proto() set_bit(HCI_UART_PROTO_INIT) hci_uart_register_dev() tty write wakeup hci_uart_tty_wakeup() hci_uart_tx_wakeup() schedule_work(&hu->write_work) proto->open(hu) // initializes hu->priv hci_uart_write_work() hci_uart_dequeue() proto->dequeue(hu) // accesses hu->priv (NULL!) Fix this by moving set_bit(HCI_UART_PROTO_INIT) after proto->open() succeeds, ensuring hu->priv is initialized before any work can be scheduled.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-23146 since 01/13/2026. The exploitability is told to be difficult. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 299221 (Linux Distros Unpatched Vulnerability : CVE-2026-23146), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.249, 5.15.199, 6.1.162, 6.6.123, 6.12.69 or 6.18.9 eliminates this vulnerability. Applying the patch b0a900939e7e4866d9b90e9112514b72c451e873/ccc683f597ceb28deb966427ae948e5ac739a909/937a573423ce5a96fdb1fd425dc6b8d8d4ab5779/186d147cf7689ba1f9b3ddb753ab634a84940cc9/53e54cb31e667fca05b1808b990eac0807d1dab0/03e8c90c62233382042b7bd0fa8b8900552fdb62/0c3cd7a0b862c37acbee6d9502107146cc944398 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (299221). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.248
• 5.15.198
• 6.1.161
• 6.6.122
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
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• 6.12.13
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• 6.12.59
• 6.12.60
• 6.12.61
• 6.12.62
• 6.12.63
• 6.12.64
• 6.12.65
• 6.12.66
• 6.12.67
• 6.12.68
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 299221
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-23146

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.249/5.15.199/6.1.162/6.6.123/6.12.69/6.18.9
Patch: b0a900939e7e4866d9b90e9112514b72c451e873/ccc683f597ceb28deb966427ae948e5ac739a909/937a573423ce5a96fdb1fd425dc6b8d8d4ab5779/186d147cf7689ba1f9b3ddb753ab634a84940cc9/53e54cb31e667fca05b1808b990eac0807d1dab0/03e8c90c62233382042b7bd0fa8b8900552fdb62/0c3cd7a0b862c37acbee6d9502107146cc944398

Timelineinfo

01/13/2026 CVE reserved
02/14/2026 +32 days Advisory disclosed
02/14/2026 +0 days VulDB entry created
03/18/2026 +32 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-23146 (🔒)
GCVE (CVE): GCVE-0-2026-23146
GCVE (VulDB): GCVE-100-346026

Entryinfo

Created: 02/14/2026 17:56
Updated: 03/18/2026 02:16
Changes: 02/14/2026 17:56 (59), 02/17/2026 04:37 (2), 02/19/2026 10:00 (1), 03/18/2026 02:16 (11)
Complete: 🔍
Cache ID: 216::103

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