SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityUndergoing Analysis

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 authenticated users, via a UI interaction, to read or write arbitrary files…

CRITICAL 9.0EPSS 0.48%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.48%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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 3.1
9.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
EPSS
0.48% probability · 40th percentile
CISA KEV
Not listed
Weakness
CWE-79
Source
security@synology.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.