CVE-2026-113349 PUBLISHED

OpenCATS before 0.10.0 contains a missing authorization vulnerability in CalendarUI::onEditEvent() and onDeleteEvent() that allows authenticated users to modify or delete other users' calendar events. Attackers with EDIT or DELETE access can supply arbitrary eventID values to alter or remove any user's events, including non-public ones restricted to their owner.

• lighthousekeeper1212 finder
• leediay153 from Viettel Post reporter

• https://github.com/opencats/OpenCATS/issues/720
• https://github.com/opencats/OpenCATS/commit/aa3b414c3672f5010ca26c44192aa8e72d3735bd
• OpenCATS v0.10.0 Release Notes
• https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/modules/calendar/CalendarUI.php#L555-L585
• https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/modules/calendar/CalendarUI.php#L690-L712
• https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/lib/Calendar.php#L83-L150
• VulnCheck Advisory: OpenCATS before 0.10.0 Missing Authorization in Calendar editEvent/deleteEvent

• Authorization Bypass Through User-Controlled Key CWE