XSS in Groupsession

CVE-2025-53523

Stored cross-site scripting vulnerabilities exist in GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. A logged-in user can prepare a malicious page or URL, and an arbitrary script may be executed on the web browser when another user accesses it.

Vulnerability class: XSS (Cross-Site Scripting)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (6.0th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.0% 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-2025-53523: held from 0.002 to 0.002.

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

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-53523?
CVE-2025-53523 is a medium-severity vulnerability in Groupsession, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2025-12-12.
How severe is CVE-2025-53523?
Medium severity. CVSS v3 base score is 5.4 out of 10.