What is CVE-2019-11825?

CVE-2019-11825 is a medium-severity vulnerability in Synology Calendar, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2019-06-30.

How severe is CVE-2019-11825?

Medium severity. CVSS v3 base score is 6.5 out of 10.

XSS in Synology Calendar

CVE-2019-11825

Cross-site scripting (XSS) vulnerability in Event Editor in Synology Calendar before 2.3.0-0615 allows remote attackers to inject arbitrary web script or HTML via the title parameter.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-06-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L.

EPSS exploit prediction

EPSS: 0.008 (55.9th percentile), scored 2026-10-26.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 55.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: -0.000

Affected products

Synology Calendar — versions unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.synology.com/security/advisory/Synology_SA_19_04 (Vendor Advisory)

Frequently asked questions

What is CVE-2019-11825?: CVE-2019-11825 is a medium-severity vulnerability in Synology Calendar, classified under Cross-site Scripting. CVSS score: 6.5/10. Published 2019-06-30.
How severe is CVE-2019-11825?: Medium severity. CVSS v3 base score is 6.5 out of 10.