XSS in Synology Diskstation Manager (Dsm)

CVE-2026-40534

An improper neutralization of input during web page generation ('cross-site scripting') vulnerability in Video API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows remote authenticated users to read or write limited files when the player is launched.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.1% 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-2026-40534: held from 0.003 to 0.003.

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40534?
CVE-2026-40534 is a medium-severity vulnerability in Synology Diskstation Manager (Dsm), classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-09-18.
How severe is CVE-2026-40534?
Medium severity. CVSS v3 base score is 5.4 out of 10.