CVE-2026-45156 Details
Description
Nextcloud is an open source content collaboration platform. From versions 0.3.0 to before 3.1.0, 5.0.0 to before 5.1.0, and 6.0.0 to before 6.4.0, a missing signature verification in User OIDC allowed a malicious ID4me authority to identify as any user. This issue has been patched in versions 3.1.0, 4.1.0, 5.1.0, 6.4.0 and 8.3.0.
A vulnerability exists in the User OIDC app for Nextcloud, specifically in versions 0.3.0 prior to 3.1.0, 5.0.0 prior to 5.1.0, and 6.0.0 prior to 6.4.0. The issue arises from a missing signature verification in the handling of OpenID Connect (OIDC) user authentication, which allows a malicious ID4me authority to impersonate any user. This vulnerability could lead to unauthorized identification and potentially allow for further exploitation within the application.
Users are advised to upgrade the User OIDC app to version 3.1.0, 4.1.0, 5.1.0, 6.4.0, or 8.3.0. Alternatively, the ID4me feature can be disabled in the configuration.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jun 1, 2026CISA-ADP
Assessed Jun 2, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp | [email protected] | AdvisoryRemedyVendor |
| https://github.com/nextcloud/user_oidc/pull/1285 | [email protected] | Source CodeVendor |
| https://hackerone.com/reports/3489490 | [email protected] | Issue TrackingPermission Required |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-287 | Improper Authentication | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Nextcloud | >= 0.3.0, < 3.1.0 (semver) >= 5.0.0, < 5.1.0 (semver) >= 6.0.0, < 6.4.0 (semver) |
CPE
Remediation
| |
| Nextcloud User OIDC | >= 0.3.0 (semver) >= 1.0.0 (semver) >= 1.2.0 (semver) >= 1.3.0 (semver) >= 5.0.0 (semver) >= 6.0.0 (semver) |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 22, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 1, 2026 | New CVE Received | [email protected] |