Vulnerability · Published Dec 12, 2025 · Assigned by jpcert
CVE-2025-61987
Medium 5.3
In plain English
A medium-severity security flaw 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 4% of all known vulnerabilities).
Severity (CVSS 3.0)5.3Medium
Exploit odds (30 days)0.2%top 95.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
GroupSession Free edition prior to ver5.3.0, GroupSession byCloud prior to ver5.3.3, and GroupSession ZION prior to ver5.3.2. do not validate origins in WebSockets. If a user accesses a crafted page, Chat information sent to the user may be exposed.
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-1385 · Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N