XSS in Synology Diskstation Manager (Dsm)

CVE-2026-13623

An improper neutralization of input during web page generation ('Cross-site Scripting') vulnerability in Theme API in Synology DiskStation Manager (DSM) before 7.2.1-69057-12, 7.2.2-72806-9, 7.3.2-86009-4 and 7.4-90075 allows remote authenticated users with administrator privileges to read or write limited files.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (21.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 21.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-13623: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-13623?
CVE-2026-13623 is a medium-severity vulnerability in Synology Diskstation Manager (Dsm), classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2026-09-18.
How severe is CVE-2026-13623?
Medium severity. CVSS v3 base score is 4.8 out of 10.