Stored Cross-Site Scripting in GroupSession by GroupSession
CVE-2025-66284

4.8MEDIUM

Key Information:

Vendor

Japan Total System Co.,ltd.

Status
Groupsession Free Edition
Groupsession Bycloud
Groupsession Zion
Vendor
CVE Published:
12 December 2025

What is CVE-2025-66284?

Stored cross-site scripting vulnerabilities in GroupSession can allow attackers to embed malicious scripts in web pages. When a logged-in user creates a harmful URL or page, the arbitrary script could execute in the web browser of an unsuspecting user who accesses it. This potentially leads to unauthorized access to sensitive information and impacts overall security. It is critical for users of the affected versions to update promptly to mitigate these risks.

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Affected Version(s)

GroupSession byCloud prior to ver5.7.1

GroupSession Free edition prior to ver5.7.1

GroupSession ZION prior to ver5.7.1

References

https://groupsession.jp/info/info-news/security20251208
https://jvn.jp/en/jp/JVN19940619/

CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

CVSS V3.0

Score:
5.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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