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.
References
| Link | Resource |
|---|---|
| https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769 | Patch |
| https://github.com/nextcloud/calendar/pull/6971 | Issue Tracking |
| https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv | Patch Vendor Advisory |
| https://hackerone.com/reports/3112033 | Issue Tracking Vendor Advisory |
Configurations
Configuration 1 (hide)
|
History
10 Dec 2025, 14:13
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Nextcloud calendar
Nextcloud |
|
| CPE | cpe:2.3:a:nextcloud:calendar:*:*:*:*:*:*:*:* | |
| References | () https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769 - Patch | |
| References | () https://github.com/nextcloud/calendar/pull/6971 - Issue Tracking | |
| References | () https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv - Patch, Vendor Advisory | |
| References | () https://hackerone.com/reports/3112033 - Issue Tracking, Vendor Advisory |
05 Dec 2025, 17:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-12-05 17:16
Updated : 2025-12-10 14:13
NVD link : CVE-2025-66550
Mitre link : CVE-2025-66550
CVE.ORG link : CVE-2025-66550
JSON object : View
Products Affected
nextcloud
- calendar
CWE
CWE-241
Improper Handling of Unexpected Data Type