CVE-2020-12456: Mitel MiVoice Connect Client

High severity, CVSS 8.8. EPSS: 3.1% chance of exploitation in the next 30 days.

A remote code execution vulnerability in Mitel MiVoice Connect Client before 214.100.1223.0 could allow an attacker to execute arbitrary code in the chat notification window, due to improper rendering of chat messages. A successful exploit could allow an attacker to steal session cookies, perform directory traversal, and execute arbitrary scripts in the context of the Connect client.

Affected products

• Mitel MiVoice Connect Client: before 214.100.1223.0 (fixed in 214.100.1223.0)

Published 2020-08-26. Last modified 2026-06-17.