# CVE-2026-43021: Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails

CVE-2026-43021 is fixed in linux on 1 platform by DEBIAN-CVE-2026-43021 (version 6.19.12-1), released May 15, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-43021
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0011
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 1, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43021

## Description

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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.19.12-1 | [DEBIAN-CVE-2026-43021](https://patchblox.com/security/data/fix/linux/debian-cve-2026-43021.md) | May 15, 2026 |

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Data as of 2026-11-09T13:31:49Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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