CVE-2025-66550

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CVSS 3.1

5.7 medium

EPSS

<1%p27

Published

Dec 5, 2025 (Dec 5, 2025)

Modified

Jun 17, 2026

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.

Vendors: nextcloud
Products: calendar
Weakness: CWE-241
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N

NVD CVE.org GitHub PoCs EPSS (0.3%)

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