CVE-2026-45284: CWE-284: Improper Access Control in nextcloud security-advisories
Nextcloud is an open source content collaboration platform. From version 1.3.6 to before version 8.4.0, an improper check allowed users that where provided by LDAP to still authenticate towards user OIDC after they where deleted. This issue has been patched in version 8.4.0.
AI Analysis
Technical Summary
Nextcloud versions 1.3.6 through 8.3.x contain an improper access control vulnerability (CWE-284) that allows users originally provided by LDAP to authenticate via user OIDC even after they have been deleted. This flaw arises from an insufficient check in the authentication process. The vulnerability was fixed in Nextcloud version 8.4.0.
Potential Impact
The vulnerability could allow deleted LDAP-provisioned users to continue authenticating via OIDC, potentially leading to unauthorized access with limited privileges. The CVSS 3.1 base score is 4.6 (medium), indicating a moderate impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Upgrade Nextcloud to version 8.4.0 or later, where this issue has been patched. No other official remediation or temporary fixes are indicated. Patch status is confirmed by the vendor advisory stating the fix is included in version 8.4.0.
CVE-2026-45284: CWE-284: Improper Access Control in nextcloud security-advisories
Description
Nextcloud is an open source content collaboration platform. From version 1.3.6 to before version 8.4.0, an improper check allowed users that where provided by LDAP to still authenticate towards user OIDC after they where deleted. This issue has been patched in version 8.4.0.
CVSS v3.1
Score 4.6medium
Affected software
pkg:github/nextcloud/security-advisoriesRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Nextcloud versions 1.3.6 through 8.3.x contain an improper access control vulnerability (CWE-284) that allows users originally provided by LDAP to authenticate via user OIDC even after they have been deleted. This flaw arises from an insufficient check in the authentication process. The vulnerability was fixed in Nextcloud version 8.4.0.
Potential Impact
The vulnerability could allow deleted LDAP-provisioned users to continue authenticating via OIDC, potentially leading to unauthorized access with limited privileges. The CVSS 3.1 base score is 4.6 (medium), indicating a moderate impact on confidentiality, integrity, and availability.
Mitigation Recommendations
Upgrade Nextcloud to version 8.4.0 or later, where this issue has been patched. No other official remediation or temporary fixes are indicated. Patch status is confirmed by the vendor advisory stating the fix is included in version 8.4.0.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-11T18:41:13.158Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a1de306e29bf47b503a5580
Added to database: 06/01/2026, 19:52:38 UTC
Last enriched: 06/08/2026, 20:49:16 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 105
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