CVE-2026-45155 LOW

CVE-2026-45155: Nextcloud: Private circle can be added to another circle via API

Vendor Nextcloud
Product security-advisories
Weakness CWE-639 · IDOR
Published June 1, 2026
Last update June 1, 2026

CVSS base score

2.6/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction Required
Confidentiality Low
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Nextcloud is an open source content collaboration platform. In Nextcloud Server from versions 32.0.0 to before 32.0.7 and 33.0.0 to before 33.0.1, a missing access check on API level allowed to add unknown circles by their ID directly to other circles. Since circle IDs have 62^15 complexity by default this is still unlikely to be executable at will, but if access to an ID was available via another source, memberships could be tracked like this. It is recommended that the Nextcloud Server is upgraded to 32.0.7 or 33.0.1. It is recommended that the Nextcloud Enterprise Server is upgraded to 29.0.16.14, 30.0.17.8, 31.0.14.3, 32.0.7 or 33.0.1

Key dates

02Disclosure timeline

June 1, 2026 CVE published
June 1, 2026 Record updated

Related vulnerabilities

04Related CVE