Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.9, and 33.0.0 to before 33.0.3, with the knowledge of other users’ principal URL an attacker could possibly send a request to gain full access to their calendar. Therefore, the attacker must be an authenticated user. This is because of improper authorization controls in the backend of the calendar. If the attacker had access to the calendar, they would be able to view and modify it. It is recommended that the Nextcloud Server is upgraded to 33.0.3 or 32.0.9. It is recommended that the Nextcloud Enterprise Server is upgraded to 33.0.3, 32.0.9, 31.0.14.5, 30.0.17.9, 29.0.16.16, 28.0.14.17, 27.1.11.26, 26.0.13.26, 25.0.13.29, 24.0.12.34, 23.0.12.35, 22.2.10.39, or 21.0.9.23
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.1, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction requiring only low-level privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), for affected systems. Impacting 1 product from nextcloud organizations running these solutions should prioritize assessment and patching.
Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2026-06-01T19:16:50.193
2026-06-03T17:11:29.807
Analyzed
CVSSv3.1: 8.1 (HIGH)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | nextcloud | nextcloud_server | < 32.0.9 | Yes |
| Application | nextcloud | nextcloud_server | < 33.0.3 | Yes |
| Application | nextcloud | nextcloud_server | < 21.0.9.23 | Yes |
| Application | nextcloud | nextcloud_server | < 22.2.10.39 | Yes |
| Application | nextcloud | nextcloud_server | < 23.0.12.35 | Yes |
| Application | nextcloud | nextcloud_server | < 24.0.12.34 | Yes |
| Application | nextcloud | nextcloud_server | < 25.0.13.29 | Yes |
| Application | nextcloud | nextcloud_server | < 26.0.13.26 | Yes |
| Application | nextcloud | nextcloud_server | < 27.1.11.26 | Yes |
| Application | nextcloud | nextcloud_server | < 28.0.14.17 | Yes |
| Application | nextcloud | nextcloud_server | < 29.0.16.16 | Yes |
| Application | nextcloud | nextcloud_server | < 30.0.17.9 | Yes |
| Application | nextcloud | nextcloud_server | < 31.0.14.5 | Yes |
| Application | nextcloud | nextcloud_server | < 32.0.9 | Yes |
| Application | nextcloud | nextcloud_server | < 33.0.3 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For nextcloud's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.