A stack-based buffer overflow vulnerability exists in BlueZ, the Linux Bluetooth protocol stack. (CVE-2026-80186)

CVE-2026-80186 is a stack-based buffer overflow vulnerability in BlueZ, the Linux Bluetooth protocol stack. The flaw occurs when BlueZ incorrectly parses remote names from Extended Inquiry Response data during Bluetooth discovery. A remote attacker within Bluetooth radio range can exploit this by sending a crafted EIR packet, causing a buffer overflow that may crash the bluetoothd service or enable arbitrary code execution. This vulnerability affects various Ubuntu LTS releases with BlueZ versions prior to the patched versions listed in the Ubuntu security advisory USN-8908-1. The issue is part of multiple BlueZ vulnerabilities fixed in the advisory.

Exploitation of this vulnerability can cause a denial of service by crashing the bluetoothd service. Additionally, it may allow an attacker to execute arbitrary code on the affected system. The CVSS v3.1 base score is 7.6, indicating a medium severity level with network attack vector, low attack complexity, no privileges required, and no user interaction needed. Confidentiality and integrity impacts are low, while availability impact is high.

A security update addressing this vulnerability is available from Ubuntu. Users should apply the BlueZ package updates as specified in Ubuntu Security Notice USN-8908-1. For Ubuntu 26.04 LTS, update to bluez version 5.85-4ubuntu0.3; for 24.04 LTS, 5.72-0ubuntu5.7; for 22.04 LTS, 5.64-0ubuntu1.5; for 20.04 LTS, 5.53-0ubuntu3.9+esm1; for 18.04 LTS, 5.48-0ubuntu3.9+esm3; and for 16.04 LTS, 5.37-0ubuntu5.3+esm6. Standard system updates will apply these fixes. Ubuntu Pro users have extended support options. No additional mitigations are indicated by the vendor advisory.