Vulnerability in Nextcloud Server

[ Description ]Official description

When a team was configured as "visible to everyone", the web UI correctly blocked non-members from viewing the team ("You are not a member of ..."), but the resources API endpoint could still be called directly, allowing any authenticated non-member to enumerate the team's internal resources and their identifiers. This does not grant access to the contents of the discovered resources themselves, only their existence, names, and identifiers.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund26 Oct 2026WID-SEC-2026-4185

  Nextcloud (Server, Tables, Whiteboard, Files Confidential, Collectives, Richdocuments): Multiple vulnerabilities Translated from German

  CVE-2026-77171CVE-2026-82986CVE-2026-77167+7 more CVEs

[ References ]References

• hackerone.com/reports/3511955