CVE-2021-3564: Debian Linux

Medium severity, CVSS 5.5. EPSS: 0.5% chance of exploitation in the next 30 days.

A flaw double-free memory corruption in the Linux kernel HCI device initialization subsystem was found in the way user attach malicious HCI TTY Bluetooth device. A local user could use this flaw to crash the system. This flaw affects all the Linux kernel versions starting from 3.13.

Affected products

• Debian Debian Linux: version 9.0 only
• Fedoraproject Fedora: version 34 only
• Linux Linux Kernel: from 3.13

Published 2021-06-08. Last modified 2026-06-17.