CVE-2021-41179: Nextcloud Server

Medium severity, CVSS 6.5. EPSS: 1.2% chance of exploitation in the next 30 days.

Nextcloud is an open-source, self-hosted productivity platform. Prior to Nextcloud Server versions 20.0.13, 21.0.5, and 22.2.0, the Two-Factor Authentication wasn't enforced for pages marked as public. Any page marked as `@PublicPage` could thus be accessed with a valid user session that isn't authenticated. This particularly affects the Nextcloud Talk application, as this could be leveraged to gain access to any private chat channel without going through the Two-Factor flow. It is recommended that the Nextcloud Server be upgraded to 20.0.13, 21.0.5 or 22.2.0. There are no known workarounds aside from upgrading.

Affected products

• Nextcloud Server: from 20.0.3, before 20.0.13 (fixed in 20.0.13); from 21.0.1, before 21.0.5 (fixed in 21.0.5); from 22.1.1, before 22.2.0 (fixed in 22.2.0)

Published 2021-10-25. Last modified 2026-06-17.