Buffer Overflow in Linux Kernel Bluetooth Management Layer

CVE-2026-43020

What is CVE-2026-43020?

A buffer overflow vulnerability exists in the Bluetooth management layer of the Linux kernel, where an attacker can exploit the handling of Long Term Keys (LTK). This vulnerability arises when the user-provided encryption size (enc_size) exceeds the fixed limit of a 16-byte key buffer. If oversized enc_size values are not properly rejected, it can lead to stack overflow during operations associated with LE LTK requests. This flaw necessitates that any enc_size exceeding the buffer capacity be validated to prevent invalid keys from jeopardizing the system's key storage state.

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