CVE-2025-66550

Published Dec 5, 2025

Last updated 5 months ago

Overview

Description
Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.17 and 5.2.4, when a malicious user creates a calendar event with a crafted attachment that links to a download link of a file on the same Nextcloud server, the file would be downloaded without the user confirming the action. This vulnerability is fixed in 4.7.17 and 5.2.4.
Source
security-advisories@github.com
NVD status
Analyzed
Products
calendar

Risk scores

CVSS 3.1

Type
Secondary
Base score
5.7
Impact score
3.6
Exploitability score
2.1
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-241

Social media

Hype score
Not currently trending

Configurations