Medium severity · published Oct 20, 2026
CVE-2026-113349
OpenCATS before 0.10.0 Missing Authorization in Calendar editEvent/deleteEvent
4.3
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenCATS · opencats
before 0.10.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-113349
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-113349
github.com
https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/lib/Calendar.php#L83-L150
github.com
https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/modules/calendar/CalendarUI.php#L555-L585
github.com
https://github.com/opencats/OpenCATS/blob/5781f41814f09493c7ce05b9251b5e09c1aff0cd/modules/calendar/CalendarUI.php#L690-L712
github.com
https://github.com/opencats/OpenCATS/commit/aa3b414c3672f5010ca26c44192aa8e72d3735bd
github.com
https://github.com/opencats/OpenCATS/issues/720
github.com
https://github.com/opencats/OpenCATS/releases/tag/v0.10.0
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