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.
Affected products
nextcloud: user oidc
References3
- github.com/nextcloud/security-advisories/security/advisories/GH… MitigationVendor Advisory
- github.com/nextcloud/user_oidc/pull/1340 Issue TrackingPatch
- hackerone.com/reports/3554696 Permissions Required
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 9 · as of 15 November 2026
- CWE
- CWE-284
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.