CVE-2026-40541: Synology Chat Server

Critical severity, CVSS 9.0. EPSS: 0.5% chance of exploitation in the next 30 days.

An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in extract domain in Synology Chat Server before 2.4.5-22148 allows remote authenticated users, via a UI interaction, to read or write arbitrary files and conduct denial-of-service attacks in DSM.

Affected products

• Synology Synology Chat Server: before 2.4.5-22148 (fixed in 2.4.5-22148)

Published 2026-08-28. Last modified 2026-09-01.