A flaw was found in 389 Directory Server. During SASL PLAIN authentication, a stale identity carried in a Cyrus SASL auxiliary property from a prior failed bind attempt can be installed on a connection following a subsequent, unrelated successful bind, regardless of which SASL mechanism completes that second bind. An attacker can send a SASL PLAIN bind as cn=Directory Manager with an incorrect password, then complete a SASL ANONYMOUS bind on the same connection, causing the server to grant Directory Manager authority without any valid credentials. A variant using a valid low-privileged account's own successful bind instead of an anonymous one is also possible.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

Administrators can restrict nsslapd-allowed-sasl-mechanisms to only the mechanisms actually required (e.g. GSSAPI, EXTERNAL, GSS-SPNEGO), excluding PLAIN. Since the exploit chain requires the first bind attempt to be a failed SASL PLAIN bind as cn=Directory Manager, removing PLAIN from the allowed mechanism list prevents that step entirely — this blocks both the originally reported variant (valid low-privileged account) and the zero-credential SASL ANONYMOUS variant, since both depend on the same initial PLAIN bind to plant the stale identity.

History

Tue, 08 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Critical


Mon, 07 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Description A flaw was found in 389 Directory Server. During SASL PLAIN authentication, a stale identity carried in a Cyrus SASL auxiliary property from a prior failed bind attempt can be installed on a connection following a subsequent, unrelated successful bind, regardless of which SASL mechanism completes that second bind. An attacker can send a SASL PLAIN bind as cn=Directory Manager with an incorrect password, then complete a SASL ANONYMOUS bind on the same connection, causing the server to grant Directory Manager authority without any valid credentials. A variant using a valid low-privileged account's own successful bind instead of an anonymous one is also possible.
Title 389-ds-base: 389-ds-base: sasl plain authentication allows privilege escalation to directory manager via stale identity in cyrus sasl auxiliary property
First Time appeared Redhat
Redhat directory Server
Redhat enterprise Linux
Weaknesses CWE-287
CPEs cpe:/a:redhat:directory_server:11
cpe:/a:redhat:directory_server:12
cpe:/a:redhat:directory_server:13
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat directory Server
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-09-07T14:14:53.799Z

Reserved: 2026-08-05T08:26:17.044Z

Link: CVE-2026-18922

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-07T15:17:31.157

Modified: 2026-09-07T15:17:31.157

Link: CVE-2026-18922

cve-icon Redhat

Severity : Critical

Publid Date: 2026-09-07T12:33:00Z

Links: CVE-2026-18922 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-07T15:45:17Z

Weaknesses