CVE-2022-24838: Nextcloud Calendar

Critical severity, CVSS 9.8. EPSS: 33% chance of exploitation in the next 30 days.

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:<BOOKING USER'S EMAIL> ` SMTP command and begin injecting arbitrary SMTP commands. It is recommended that Calendar is upgraded to 3.2.2. There are no workaround available.

Affected products

• Nextcloud Calendar: before 3.2.2 (fixed in 3.2.2)

Published 2022-04-11. Last modified 2026-06-17.