CVE-2025-66511: nextcloud calendar

csirt@kutim:~/threat-intel/cve/CVE-2025-66511

CVSS 6.5 · Medium EPSS 0,30%

Kerentanan Use of Insufficiently Random Values pada nextcloud calendar. Skor CVSS 3.1 6.5 (Medium) menurut NVD.

Deskripsi (NVD)

Nextcloud Calendar is a calendar app for Nextcloud. Prior to 6.0.3, the Calendar app generates participant tokens for meeting proposals using a hash function, allowing an attacker to compute valid participant tokens, which allowed them to request details and submit dates in meeting proposals. The tokens are not purely random generated. This vulnerability is fixed in 6.0.3.

Rincian

Terbit di NVD: 5 Desember 2025
Terakhir diubah: 17 Juni 2026
Status NVD: Analyzed
CVSS 3.1: 6.5 (Medium), sumber NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N · uraikan di kalkulator
Jenis kelemahan (CWE): CWE-330: Use of Insufficiently Random Values
EPSS (30 hari): 0,30% peluang dieksploitasi; lebih tinggi dari 20,4% CVE lain

Produk dan versi terdampak

Vendor	Produk	Versi terdampak
nextcloud	calendar	Versi 6.0.0 hingga sebelum 6.0.3

> Data dari konfigurasi CPE di NVD.

Referensi dan perbaikan

https://github.com/nextcloud/security-advisories/security/advisories/GHSA-whm3-vv55-gf27 patch · advisory vendor
https://hackerone.com/reports/3385434 permissions required · advisory vendor
https://github.com/nextcloud/calendar/commit/8de14ae87f321f5f09280d9895a27d54d24f33fb patch
https://github.com/nextcloud/calendar/pull/7659 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.