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.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://github.com/nextcloud/calendar/commit/f41650c3681fc4a4130eb883f5c0899c011326b3 Patch
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-7x2j-2674-fj95 Patch, Vendor Advisory
- https://hackerone.com/reports/3275810 Issue Tracking, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 3.3 · nextcloudNVD modified 2026-10-18 14:10
Affected (CPE criteria) 8
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:*:*:*:*:*:*
References 4
- https://github.com/nextcloud/calendar/commit/f41650c3681fc4a4130eb883f5c0899c011326b3 Patch
- https://github.com/nextcloud/calendar/pull/7537 Issue Tracking
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-7x2j-2674-fj95 Patch, Vendor Advisory
- https://hackerone.com/reports/3275810 Issue Tracking, Vendor Advisory