Nextcloud is an open source content collaboration platform. From versions 5.5.13 to before 5.5.17, and 6.2.0 to before 6.2.3, an authenticated user can enumerate users on the same Nextcloud instance by using the Calendar app's endpoint for suggesting attendees. The sharing restrictions, applied to other endpoints, were not effective here. This issue has been patched in versions 5.5.17 and 6.2.3.
History

Mon, 01 Jun 2026 21:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 01 Jun 2026 19:00:00 +0000

Type Values Removed Values Added
Description Nextcloud is an open source content collaboration platform. From versions 5.5.13 to before 5.5.17, and 6.2.0 to before 6.2.3, an authenticated user can enumerate users on the same Nextcloud instance by using the Calendar app's endpoint for suggesting attendees. The sharing restrictions, applied to other endpoints, were not effective here. This issue has been patched in versions 5.5.17 and 6.2.3.
Title Nextcloud: Calendar app leaked user identifiers via attendee suggestion endpoint
Weaknesses CWE-200
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-06-01T19:13:25.363Z

Reserved: 2026-05-11T20:14:43.200Z

Link: CVE-2026-45286

cve-icon Vulnrichment

Updated: 2026-06-01T19:13:04.269Z

cve-icon NVD

Status : Received

Published: 2026-06-01T19:16:50.957

Modified: 2026-06-01T19:16:50.957

Link: CVE-2026-45286

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-01T20:45:25Z