Synology - Synology Chat Server - CRITICAL - CVE-2026-40541. A vulnerability exists in Synology Chat Server prior to version 2.4.5-22148 due to improper input handling during web page generation. This flaw permits remote authenticated users to exploit the system through UI interactions, potentially allowing them to read or write arbitrary files. Additionally, this vulnerability may facilitate denial-of-service attacks, negatively impacting the availability and functionality of the chat service.