CVE-2026-45155

A flaw was found in Nextcloud Server. A missing access check at the API Application Programming Interface level could allow an authenticated attacker, who has access to a circle ID from another source, to add unknown circles to other circles. This could lead to the disclosure of circle membership...

CVE-2026-45155 Nextcloud: Private circle can be added to another circle via API

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.7 and 33.0.0 to before 33.0.1, a missing access check on API level allowed to add unknown circles by their ID directly to other circles. Since circle IDs have 62^15 complexity by...

CVE-2026-45155

Nextcloud Server is affected by CVE-2026-45155 due to a missing API-level access check that allows adding unknown circle IDs to other circles. Affected versions are 32.0.0–32.0.6 and 33.0.0–33.0.0 (i.e., before 32.0.7 and before 33.0.1). The underlying issue could enable unauthorized membership t...