Vulnerability · Published Aug 28, 2026 · Assigned by synology
CVE-2026-40541
Critical 9.0
In plain English
A critical-severity cross-site scripting in Synology Chat Server from Synology. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).
Severity (CVSS 3.1)9.0Critical
Exploit odds (30 days)0.5%top 57.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Synology | Synology Chat Server | * – before 2.4.5-22148 |
Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
References
- Synology-SA-26:10 Synology Chat Server vendor-advisory