CVE-2026-45286 | BDVDB-2026-337107 Detail

nextcloudsecurity-advisories

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.

Impact#

Per CVSS v3.1: confidentiality impact low, integrity impact none, availability impact none. Attack vector: network.

Weaknesses#

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References#

Exploit#

No public exploit known

History#

Version 12026-06-01Record published in the CVE List.

Published

Published: 2026-06-01
Last modified: 2026-06-01

Vendor information

Vendor: nextcloud
Product: security-advisories

All nextcloud vulnerabilities

Score

4.3 Medium

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 20.7.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Information Disclosure

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
>= 5.5.13, < 5.5.17
Fixed
Not stated
Vulnerable
>= 6.2.0, < 6.2.3
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

4.3 Medium

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	Low
User Interaction	None
Scope	Unchanged
Confidentiality	Low
Integrity	None
Availability	None

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).