CVE-2025-66550: nextcloud calendar

csirt@kutim:~/threat-intel/cve/CVE-2025-66550

CVSS 5.7 · Medium EPSS 0,34%

Kerentanan Improper Handling of Unexpected Data Type pada nextcloud calendar. Skor CVSS 3.1 5.7 (Medium) menurut github.com.

Deskripsi (NVD)

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.

Rincian

Terbit di NVD: 5 Desember 2025
Terakhir diubah: 17 Juni 2026
Status NVD: Analyzed
CVSS 3.1: 5.7 (Medium), sumber github.com
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N · uraikan di kalkulator
Jenis kelemahan (CWE): CWE-241: Improper Handling of Unexpected Data Type
EPSS (30 hari): 0,34% peluang dieksploitasi; lebih tinggi dari 25,7% CVE lain

Produk dan versi terdampak

Vendor	Produk	Versi terdampak
nextcloud	calendar	Versi 4.0.0 hingga sebelum 4.7.17
nextcloud	calendar	Versi 5.0.0 hingga sebelum 5.2.4

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f29c-ppmv-8mcv patch · advisory vendor
https://hackerone.com/reports/3112033 issue tracking · advisory vendor
https://github.com/nextcloud/calendar/commit/63a6c398db01391eb9fd5297a0d4c3d6e614f769 patch
https://github.com/nextcloud/calendar/pull/6971 issue tracking

Sumber: NVD · CVE.org · EPSS. Halaman ini disusun otomatis dari data tersebut; pembaruan terakhir 5 Okt 2026, 20:11 WITA. Kalau sistem di Perangkat Daerah memakai produk ini dan butuh bantuan, laporkan lewat kanal pelaporan.