CVE-2026-43021: Linux kernel · Bluetooth: hci_sync: fix leaks when hci_cmd_sync_queue_once fails
Affects Linux kernelSource CVE Database V5
Not known to be exploited : upgrade to aca377208e7f7322bf4e107cdec6e7d7e8aa7a88 or 7fd74178d4b16dcf47179da634ea9d7c02e3608b when convenient.
Data as of 6 Nov 2026, 16:33 UTC
Rated Low by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in aca377208e7f7322bf4e107cdec6e7d7e8aa7a88, 7fd74178d4b16dcf47179da634ea9d7c02e3608b
Exploitation evidence
Disclosed: evidence found.
CVE published 1 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade Linux kernel to aca377208e7f7322bf4e107cdec6e7d7e8aa7a88 or 7fd74178d4b16dcf47179da634ea9d7c02e3608b.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
AI-suggested
The issue is fixed in the Linux kernel commits aca377208e7f7322bf4e107cdec6e7d7e8aa7a88 and 7fd74178d4b16dcf47179da634ea9d7c02e3608b. Applying these patches or upgrading to a kernel version that includes these fixes will remediate the vulnerability.
Description
A vulnerability in the Linux kernel Bluetooth subsystem (hci_sync) caused memory leaks when the function hci_cmd_sync_queue_once() failed, due to the destroy callback not being called. This issue has been fixed in specific Linux kernel commits.