CVE-2026-45286

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-01 19:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-22 08:10 UTC Last updatedMost recent change to the record

Details

Published

2026-06-01 19:16 UTC

Last modified

2026-07-22 08:10 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-200 · Information exposure

Record status

Analyzed

Affected

• Nextcloud Calendar < 5.5.17
• Nextcloud Calendar < 6.2.3

Attack profile CVSS 3.1 · 4.3

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None