CVE-2023-33183: Nextcloud Calendar

Medium severity, CVSS 4.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Calendar app for Nextcloud easily sync events from various devices with your Nextcloud. Some internal paths of the website are disclosed when the SMTP server is unavailable. It is recommended that the Calendar app is updated to 3.5.5 or 4.2.3

Affected products

• Nextcloud Calendar: before 3.5.5 (fixed in 3.5.5); from 4.0.0, before 4.2.3 (fixed in 4.2.3)

Published 2023-05-30. Last modified 2026-06-17.