CVE-2026-45811 is a classic buffer overflow vulnerability in Apache NimBLE versions prior to 1.10.0. The flaw arises because the HCI socket transport does not verify whether a received HCI event fits within the configured event pool before copying it, potentially leading to memory corruption. Exploitation requires either a misconfigured pool size or a malicious or compromised controller on the HCI socket link, meaning remote over-the-air Bluetooth exploitation is not possible. The issue is addressed in Apache NimBLE version 1.10.0.

Successful exploitation can lead to high impact including confidentiality, integrity, and availability compromise due to buffer overflow. However, exploitation is limited to scenarios involving local or direct access to the HCI socket link with a malicious or compromised controller or misconfiguration, not remote Bluetooth attacks.

Upgrade Apache NimBLE to version 1.10.0 or later where this vulnerability is fixed. Since the vulnerability requires specific conditions (misconfigured pool size or malicious controller on the HCI socket), ensure proper configuration of the event pool size and restrict access to the HCI socket link to trusted controllers. Patch status is confirmed fixed in version 1.10.0.