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.
References (4)
Core 4
Core References
Patch, Vendor Advisory x_refsource_confirm
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv
Issue Tracking x_refsource_misc
https://github.com/nextcloud/calendar/pull/6971
Patch x_refsource_misc
https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769
Issue Tracking, Vendor Advisory x_refsource_misc
https://hackerone.com/reports/3112033
Scores
CVSS v3
5.7
EPSS
0.0002
EPSS Percentile
7.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-241
Status
published
Products (1)
nextcloud/calendar
4.0.0 - 4.7.17
Published
Dec 05, 2025
Tracked Since
Feb 18, 2026