What is CVE-2025-61950?

CVE-2025-61950 is a medium-severity vulnerability in Groupsession, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2025-12-12.

How severe is CVE-2025-61950?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in Groupsession

CVE-2025-61950

In GroupSession, a Circular notice can be created with its memo field non-editable, but the authorization check is improperly implemented. With some crafted request, a logged-in user may alter the memo field. The affected products and vers…

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.002 (7.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.

Affected products

Groupsession
Japan Total System Co.,ltd. Groupsession Bycloud — versions prior to ver5.3.3
Japan Total System Co.,ltd. Groupsession Free Edition — versions prior to ver5.3.0
Japan Total System Co.,ltd. Groupsession Zion — versions prior to ver5.3.2

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

vultures@jpcert.or.jp (Vendor Advisory)
vultures@jpcert.or.jp (Third Party Advisory)

Frequently asked questions

What is CVE-2025-61950?: CVE-2025-61950 is a medium-severity vulnerability in Groupsession, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2025-12-12.
How severe is CVE-2025-61950?: Medium severity. CVSS v3 base score is 4.3 out of 10.