Review reviewHigh

CVE-2026-45284

nextcloud security-advisories, user oidc

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
8.8
EPSS
0.19%
9.26% percentile
CISA KEV
Not listed
Published
2026.06.02
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.19%
Technical severityCVSS 8.8

Vulnerability overview

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 product and versions

Product
nextcloud security-advisories, user oidc
Affected versions
>= >= 1.3.6, < 8.4.0, >= 1.3.6 < 8.4.0
Fixed versions
8.4.0

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that nextcloud security-advisories, user oidc and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-284
CVE-2026-45284 — nextcloud security-advisories, user oidc | SECUFOCUS NOW