Nextcloud Calendar vulnerabilities

CVE-2025-66550 [MEDIUM] CWE-241 CVE-2025-66550: Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a calendar event with a crafted attachment that links to a download link of a file on the same Nextcloud server, the file would be downloaded without the user confirming the action. This vulnerability is fixed in 4.7.17 and 5.2.4.

CVE-2025-66511 [MEDIUM] CWE-330 CVE-2025-66511: Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates parti Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for meeting proposals using a hash function, allowing an attacker to compute valid participant tokens, which allowed them to request details and submit dates in meeting proposals. The tokens are not purely random generated. This vulnerab

CVE-2025-66546 [LOW] CWE-639 CVE-2025-66546: Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1.

CVE-2024-37316 [MEDIUM] CWE-241 CVE-2024-37316: Nextcloud Calendar is a calendar app for Nextcloud. Authenticated users could create an event with m Nextcloud Calendar is a calendar app for Nextcloud. Authenticated users could create an event with manipulated attachment data leading to a bad redirect for participants when clicked. It is recommended that the Nextcloud Calendar App is upgraded to 4.6.8 or 4.7.2.

CVE-2023-48308 [MEDIUM] CWE-1258 CVE-2023-48308: Nextcloud/Cloud is a calendar app for Nextcloud. An attacker can gain access to stacktrace and inter Nextcloud/Cloud is a calendar app for Nextcloud. An attacker can gain access to stacktrace and internal paths of the server when generating an exception while editing a calendar appointment. It is recommended that the Nextcloud Calendar app is upgraded to 4.5.3

CVE-2023-45150 [MEDIUM] CWE-400 CVE-2023-45150: Nextcloud calendar is a calendar app for the Nextcloud server platform. Due to missing precondition Nextcloud calendar is a calendar app for the Nextcloud server platform. Due to missing precondition checks the server was trying to validate strings of any length as email addresses even when megabytes of data were provided, eventually making the server busy and unresponsive. It is recommended that the Nextcloud Calendar app is upgraded to 4.4.4. The

CVE-2023-33183 [MEDIUM] CWE-285 CVE-2023-33183: Calendar app for Nextcloud easily sync events from various devices with your Nextcloud. Some interna 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

CVE-2022-24838 [CRITICAL] CWE-74 CVE-2022-24838: Nextcloud Calendar is a calendar application for the nextcloud framework. SMTP Command Injection in Nextcloud Calendar is a calendar application for the nextcloud framework. SMTP Command Injection in Appointment Emails via Newlines: as newlines and special characters are not sanitized in the email value in the JSON request, a malicious attacker can inject newlines to break out of the `RCPT TO: ` SMTP command and begin injecting arbitrary SMTP comm

CVE-2018-3763 [MEDIUM] CWE-79 CVE-2018-3763: In Nextcloud Calendar before 1.5.8 and 1.6.1, a missing sanitization of search results for an autoco In Nextcloud Calendar before 1.5.8 and 1.6.1, a missing sanitization of search results for an autocomplete field could lead to a stored XSS requiring user-interaction. The missing sanitization only affected group names, hence malicious search results could only be crafted by privileged users like admins or group admins.