CVE-2021-20786: Groupsession

Medium severity, CVSS 4.3. EPSS: 0.5% chance of exploitation in the next 30 days.

Cross-site request forgery (CSRF) vulnerability in GroupSession (GroupSession Free edition from ver2.2.0 to the version prior to ver5.1.0, GroupSession byCloud from ver3.0.3 to the version prior to ver5.1.0, and GroupSession ZION from ver3.0.3 to the version prior to ver5.1.0) allows a remote attacker to hijack the authentication of administrators via a specially crafted URL.

Affected products

• Groupsession Groupsession: from 2.20, before 5.1.0 (fixed in 5.1.0)
• Groupsession Groupsession Bycloud: from 3.0.3, before 5.1.0 (fixed in 5.1.0)
• Groupsession Groupsession Zion: from 3.0.3, before 5.1.0 (fixed in 5.1.0)

Published 2021-07-30. Last modified 2026-06-17.