Authenticated memo alteration via user-controlled authorization key
Published Dec 12, 2025 · Updated Dec 12, 2025
Authorization bypass in affected GroupSession editions allows remote authenticated users to alter non-editable Circular notice memos. The Circular notice handler accepts a crafted user-controlled key without correctly enforcing the memo's edit restriction; the vendor withholds the affected function and reproduction steps. Exposure requires a logged-in account and affects Free edition before 5.3.0, byCloud before 5.3.3, and ZION before 5.3.2; only memo integrity is reported.
Summary
What happened
Authorization bypass in affected GroupSession editions allows remote authenticated users to alter non-editable Circular notice memos. The Circular notice handler accepts a crafted user-controlled key without correctly enforcing the memo's edit restriction; the vendor withholds the affected function and reproduction steps. Exposure requires a logged-in account and affects Free edition before 5.3.0, byCloud before 5.3.3, and ZION before 5.3.2; only memo integrity is reported.
The record
- CVE
- CVE-2025-61950
- Published
- Dec 12, 2025
- Updated
- Dec 12, 2025
- Vendor
- Japan Total System Co.,Ltd.
- Product
- GroupSession ZION
- Classifications
- CWE-639, T1565.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 12, 2025CVE publishedPublication date reported by the CVE source.
- Dec 12, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=prior to ver5.3.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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