The vulnerability of the Nextcloud Calendar application, a cloud-based software for creating and using Nextcloud data storage, relates to the use of insufficiently random values. This vulnerability allows attackers to compromise the confidentiality and integrity of the protected information.
🗓️ 19 Mar 2026 00:00:00Reported by FSTEC of Russia — Information Security Threat DatabaseType 
bdu_fstec🔗 bdu.fstec.ru👁 8 Views
| Reporter | Title | Published | Views | Family All 13 |
|---|---|---|---|---|
 | CVE-2025-66511 | 5 Dec 202514:50 | – | circl |
 | Nextcloud Calendar 安全特征问题漏洞 | 5 Dec 202500:00 | – | cnnvd |
 | Nextcloud Calendar Security Feature Issue Vulnerability | 10 Dec 202500:00 | – | cnvd |
 | CVE-2025-66511 | 5 Dec 202516:42 | – | cve |
 | CVE-2025-66511 Nextcloud Calendar app used predictable proposal participant tokens | 5 Dec 202516:42 | – | cvelist |
 | EUVD-2025-201444 | 5 Dec 202516:42 | – | euvd |
 | Calendar app used predictable proposal participant tokens | 5 Dec 202508:08 | – | nextcloud |
 | Nextcloud: Predictable proposal participant tokens enable unauthorized access and vote submission | 15 Oct 202516:45 | – | hackerone |
 | CVE-2025-66511 | 5 Dec 202517:16 | – | nvd |
 | PT-2025-49266 | 5 Dec 202500:00 | – | ptsecurity |
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19 Mar 2026 00:00Current
5.8Medium risk
Vulners AI Score5.8
CVSS 26.4
CVSS 36.5
EPSS0.00288