CVE-2026-113349
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.
Does this matter?
Lower severity and a low EPSS score (0.26%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 4.0
- 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.26% probability · 18th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-639
- Source
- disclosure@vulncheck.com
EPSS moved from 0.2% on 21 October 2026 to 0.3% on 26 October 2026.
References
- https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/lib/Calendar.php#L83-L150
- 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/commit/aa3b414c3672f5010ca26c44192aa8e72d3735bd
- https://github.com/opencats/OpenCATS/issues/720
- https://github.com/opencats/OpenCATS/releases/tag/v0.10.0
- https://www.vulncheck.com/advisories/opencats-before-0.10.0-missing-authorization-in-calendar-editevent-deleteevent
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.