CVE-2026-45286

MEDIUM EPSS 19.8%
Published Jun 1, 20264w ago · Modified Jun 17, 20261w ago
4.3 CVSS 3.1
Medium
Find Similar
Published Jun 1, 2026 4w ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
4.3
Exploitability
2.8
Impact
1.4
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality Low
Integrity None
Availability None

Threat Intelligence

EPSS Exploit Probability
19.8% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor Information Exposure

Affected Products 2

VendorProductVersionRange
nextcloudcalendar*≥5.5.13  –  <5.5.17
nextcloudcalendar*≥6.2.0  –  <6.2.3

References 4

  • github.com https://github.com/nextcloud/calendar/issues/7971
    ExploitIssue TrackingPatch
  • github.com https://github.com/nextcloud/calendar/pull/8197
    Issue TrackingPatch
  • github.com https://github.com/nextcloud/security-advisories/security/advisories/GHSA-r697-74m9-gvf2
    MitigationVendor Advisory
  • hackerone.com https://hackerone.com/reports/3540663
    Permissions Required

Remediation

  • github.com https://github.com/nextcloud/calendar/issues/7971
    ExploitIssue TrackingPatch
  • github.com https://github.com/nextcloud/calendar/pull/8197
    Issue TrackingPatch