CVE-2026-40541 PUBLISHED

Assigner: synology
Reserved: 14.04.2026 Published: 28.08.2026 Updated: 28.08.2026

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.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
CVSS Score: 9

Attack Vector	Network	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	Low	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

Product Status

Vendor	Synology
Product	Synology Chat Server
Versions	Default: affected affected from * to 2.4.5-22148 (excl.)

Credits

Lam Jun Rong and Javier Koh, Cyber Specialists of the Digital and Intelligence Service (DIS) working with the Centre for Strategic Infocomm Technologies (CSIT) and Dr Joseph Teo, CSIT finder

References

Synology-SA-26:10 Synology Chat Server

Problem Types

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') CWE