Auth bypass in Red Hat Directory Server 11
CVE-2026-18651
A flaw was found in 389 Directory Server. During SASL PLAIN authentication, the server installs connection-level bind credentials before performing the account-lock check. If the account is subsequently found to be locked, the bind is reported as failed to the client, but the already-installed authenticated state on the connection is not reverted. A client that supplies valid credentials for an account that has been administratively locked can continue to use the same connection with that account's privileges, defeating account lock as an access-revocation control.
Vulnerability class: Broken Authentication
EPSS: 0.002 (6.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
Affected products
Weakness classification (CWE)
References
- secalert@redhat.com (x_refsource_REDHAT, vdb-entry, Vendor Advisory)
- secalert@redhat.com (x_refsource_REDHAT, issue-tracking, Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-18651?
- CVE-2026-18651 is a medium-severity vulnerability in Red Hat Directory Server 11, classified under Improper Authentication. CVSS score: 5.4/10. Published 2026-08-03.
- How severe is CVE-2026-18651?
- Medium severity. CVSS v3 base score is 5.4 out of 10.