VDB-360695 · CVE-2026-43021 · EUVD-2026-26620

Linux Kernel up to 6.19.11 Bluetooth hci_cmd_sync_queue_once memory leak

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5.5	$0-$5k	0.00

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.19.11. Impacted is the function hci_cmd_sync_queue_once of the component Bluetooth. The manipulation leads to memory leak. This vulnerability is referenced as CVE-2026-43021. The attack needs to be initiated within the local network. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.19.11. This issue affects the function hci_cmd_sync_queue_once of the component Bluetooth. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails When hci_cmd_sync_queue_once() returns with error, the destroy callback will not be called. Fix leaking references / memory on these failures.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-43021 since 05/01/2026. The exploitation is known to be easy. Access to the local network is required for this attack to succeed. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 6.19.12 eliminates this vulnerability. Applying the patch 7fd74178d4b16dcf47179da634ea9d7c02e3608b/aca377208e7f7322bf4e107cdec6e7d7e8aa7a88 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 EUVD (EUVD-2026-26620). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

Version

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: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory leak
CWE: CWE-401 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
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

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.19.12
Patch: 7fd74178d4b16dcf47179da634ea9d7c02e3608b/aca377208e7f7322bf4e107cdec6e7d7e8aa7a88

Timelineinfo

05/01/2026 Advisory disclosed
05/01/2026 +0 days CVE reserved
05/01/2026 +0 days VulDB entry created
05/03/2026 +2 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-43021 (🔒)
GCVE (CVE): GCVE-0-2026-43021
GCVE (VulDB): GCVE-100-360695
EUVD: 🔒

Entryinfo

Created: 05/01/2026 17:59
Updated: 05/03/2026 04:01
Changes: 05/01/2026 17:59 (59), 05/03/2026 04:01 (1)
Complete: 🔍
Cache ID: 216::103