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CVE-2026-45281

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
01/06/2026
Last modified:
03/06/2026

Description

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

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N CVSS v3.1 Severity and Metrics:

Base Score: 8.10 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): High
Availability (A): None

Base Score 3.x
8.10
Severity 3.x
HIGH

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* 32.0.0 (including) 32.0.9 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* 33.0.0 (including) 33.0.3 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 21.0.0 (including) 21.0.9.23 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 22.0.0 (including) 22.2.10.39 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 23.0.0 (including) 23.0.12.35 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 24.0.0 (including) 24.0.12.34 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 25.0.0 (including) 25.0.13.29 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 26.0.0 (including) 26.0.13.26 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 27.0.0 (including) 27.1.11.26 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 28.0.0 (including) 28.0.14.17 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 29.0.0 (including) 29.0.16.16 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 30.0.0 (including) 30.0.17.9 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 31.0.0 (including) 31.0.14.5 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 32.0.0 (including) 32.0.9 (excluding)
cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* 33.0.0 (including) 33.0.3 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools