CVE-2025-66550

MEDIUM

Nextcloud Calendar <4.7.17-5.2.4 - Info Disclosure

Title source: llm

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.

Scores

CVSS v3 5.7
EPSS 0.0003
EPSS Percentile 6.3%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N

Classification

CWE
CWE-241
Status published

Affected Products (1)

nextcloud/calendar < 4.7.17

Timeline

Published Dec 05, 2025
Tracked Since Feb 18, 2026