CVE-2023-23943: Nextcloud Mail

Medium severity, CVSS 4.3. EPSS: 0.9% chance of exploitation in the next 30 days.

Nextcloud mail is an email app for the nextcloud home server platform. In affected versions the SMTP, IMAP and Sieve host fields allowed to scan for internal services and servers reachable from within the local network of the Nextcloud Server. It is recommended that the Nextcloud Maill app is upgraded to 1.15.0 or 2.2.2. The only known workaround for this issue is to completely disable the nextcloud mail app.

Affected products

• Nextcloud Mail: before 1.15.0 (fixed in 1.15.0); from 2.2.0, before 2.2.2 (fixed in 2.2.2)

Published 2023-02-06. Last modified 2026-06-17.