Vulnerability · Published Dec 12, 2025 · Assigned by jpcert
CVE-2025-53523
Medium 5.4
In plain English
A medium-severity cross-site scripting in GroupSession byCloud from Japan Total System Co.,Ltd.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities).
Severity (CVSS 3.0)5.4Medium
Exploit odds (30 days)0.2%top 93.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Japan Total System Co.,Ltd. | GroupSession Free edition | prior to ver5.3.0 |
| Japan Total System Co.,Ltd. | GroupSession byCloud | prior to ver5.3.3 |
| Japan Total System Co.,Ltd. | GroupSession ZION | prior to ver5.3.2 |
Weakness: CWE-79 · Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N