Description
Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for meeting proposals using a hash function, allowing an attacker to compute valid participant tokens, which allowed them to request details and submit dates in meeting proposals. The tokens are not purely random generated. This vulnerability is fixed in 6.0.3.
Scores
CVSS v3
4.8
EPSS
0.0003
EPSS Percentile
8.8%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-330
Status
published
Products (1)
nextcloud/calendar
6.0.0 - 6.0.3
Published
Dec 05, 2025
Tracked Since
Feb 18, 2026