Critical severity · published Aug 28, 2026
CVE-2026-40541
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…
9.0
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 42% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
SC
Synology Chat Server · Synology
before 2.4.5-22148 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40541
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40541
www.synology.com
https://www.synology.com/en-global/security/advisory/Synology_SA_26_10
More from Synology Chat Server
6.5
CVE-2026-9548
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…
4.3
CVE-2026-9491
A server-ide request forgery (SSRF) vulnerability in webhook in Synology Chat Server before 2.4.5-22148 allows remote authenticated users to obtain non-sensitive information