CVE-2026-18922

Summary

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.

Affected Software

VendorProductVersion RangeStatus
Red HatRed Hat Directory Server 11.7 E4S for RHEL 88080020260903102346.f969626e < *unaffected
Red HatRed Hat Directory Server 11.9 for RHEL 88100020260904171440.37ed7c03 < *unaffected
Red HatRed Hat Directory Server 12.2 E4S for RHEL 99020020260903155914.1674d574 < *unaffected
Red HatRed Hat Directory Server 12.4 E4S for RHEL 99040020260903102623.1674d574 < *unaffected
Red HatRed Hat Enterprise Linux 100:3.2.0-10.el10_2 < *unaffected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support0:3.0.6-21.el10_0 < *unaffected
Red HatRed Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION0:1.2.11.15-97.el6_10.1 < *unaffected
Red HatRed Hat Enterprise Linux 7 Extended Lifecycle Support0:1.3.11.1-15.el7_9 < *unaffected
Red HatRed Hat Enterprise Linux 88100020260904155442.25e700aa < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support8040020260901171549.96015a92 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On8040020260901171549.96015a92 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support8060020260901145727.824efc52 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On8060020260901145727.824efc52 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service8080020260831180218.6dbb3803 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions8080020260831180218.6dbb3803 < *unaffected
Red HatRed Hat Enterprise Linux 90:2.8.0-10.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 9.2 Update Services for SAP Solutions0:2.2.4-22.el9_2 < *unaffected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutions0:2.4.5-29.el9_4 < *unaffected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Support0:2.6.1-24.el9_6 < *unaffected

Weaknesses

  • CWE-287: Improper Authentication

Workarounds

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.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References