CVE-2025-66511 — Nextcloud Calendar app used predictable proposal participant tokens
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 attack…
Published: 2025-12-05 · CVSS: 4.8 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7