CVE-2025-66511

Published Dec 5, 2025

Last updated 5 months ago

Overview

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.
Source
security-advisories@github.com
NVD status
Analyzed
Products
calendar

Risk scores

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
2.5
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-330

Social media

Hype score
Not currently trending

Configurations