Description
Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1.
Published: 2025-12-05
Score: 3.3 Low
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Tue, 09 Dec 2025 16:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:-:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:rc1:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:rc2:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:rc3:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:rc4:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:rc5:*:*:*:*:*:*
cpe:2.3:a:nextcloud:calendar:6.0.0:rc6:*:*:*:*:*:*

Tue, 09 Dec 2025 10:15:00 +0000

Type Values Removed Values Added
First Time appeared Nextcloud
Nextcloud calendar
Vendors & Products Nextcloud
Nextcloud calendar

Fri, 05 Dec 2025 19:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Fri, 05 Dec 2025 17:00:00 +0000

Type Values Removed Values Added
Description Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1.
Title Nextcloud Calendar app allowed booking appointments without the generated token
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 3.3, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}


Subscriptions

Nextcloud Calendar
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-12-05T18:32:44.271Z

Reserved: 2025-12-04T15:52:26.549Z

Link: CVE-2025-66546

cve-icon Vulnrichment

Updated: 2025-12-05T18:32:34.528Z

cve-icon NVD

Status : Analyzed

Published: 2025-12-05T17:16:05.163

Modified: 2025-12-09T16:36:01.357

Link: CVE-2025-66546

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-12-09T10:05:54Z

Weaknesses