CVE-2026-45286

4.3 MEDIUM
Published: June 01, 2026 Modified: June 03, 2026
View on NVD

Description

Nextcloud is an open source content collaboration platform. From versions 5.5.13 to before 5.5.17, and 6.2.0 to before 6.2.3, an authenticated user can enumerate users on the same Nextcloud instance by using the Calendar app's endpoint for suggesting attendees. The sharing restrictions, applied to other endpoints, were not effective here. This issue has been patched in versions 5.5.17 and 6.2.3.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/nextcloud/calendar/issues/7971
Source: security-advisories@github.com
Exploit Issue Tracking Patch
https://github.com/nextcloud/calendar/pull/8197
Source: security-advisories@github.com
Issue Tracking Patch
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r697-74m9-gvf2
Source: security-advisories@github.com
Mitigation Vendor Advisory
https://hackerone.com/reports/3540663
Source: security-advisories@github.com
Permissions Required

4 reference(s) from NVD

Quick Stats

CVSS v3 Score
4.3 / 10.0
EPSS (Exploit Probability)
0.3%
18th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

nextcloud