RHSA-2026:64789 - Security Advisory

Topic

An update for the 389-ds:1.4 module is now available for Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support and Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On.

Red Hat Product Security has rated this update as having a security impact of Critical. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

389 Directory Server is an LDAP version 3 (LDAPv3) compliant server. The base packages include the Lightweight Directory Access Protocol (LDAP) server and command-line utilities for server administration.

Security Fix(es):

• 389-ds-base: 389-ds-base: heap buffer overflow via SASL wrapped-record length lower-bound underflow in sasl_io_start_packet() (CVE-2026-18355)
• 389-ds-base: 389-ds-base: pre-authentication NULL pointer dereference via paged results and USE_ONE_BACKEND control in op_shared_search (CVE-2026-18453)
• 389-ds-base: 389-ds-base: SASL PLAIN authentication allows privilege escalation to Directory Manager via stale identity in Cyrus SASL auxiliary property (CVE-2026-18922)
• 389-ds-base: 389-ds: anonymous LDAP client can defeat SELFDN ACI bind-rule checks via empty bind DN (CVE-2026-76560)

Bug Fix(es) and Enhancement(s):

• lib389: set nsDS5ReplicaBindDNGroup before ensure_agreement() (JIRA:RHEL-244460)
• fix breaks replication total init when nsDS5ReplicaBindDNGroup is set after agreement creation (JIRA:RHEL-248759)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life 8.4 x86_64
• Red Hat Enterprise Linux Server - AUS 8.4 x86_64

Fixes

• BZ - 2509186 - CVE-2026-18355 389-ds-base: 389-ds-base: heap buffer overflow via SASL wrapped-record length lower-bound underflow in sasl_io_start_packet()
• BZ - 2509696 - CVE-2026-18453 389-ds-base: 389-ds-base: pre-authentication NULL pointer dereference via paged results and USE_ONE_BACKEND control in op_shared_search
• BZ - 2511388 - CVE-2026-18922 389-ds-base: 389-ds-base: SASL PLAIN authentication allows privilege escalation to Directory Manager via stale identity in Cyrus SASL auxiliary property
• BZ - 2519521 - CVE-2026-76560 389-ds-base: 389-ds: anonymous LDAP client can defeat SELFDN ACI bind-rule checks via empty bind DN

CVEs

• CVE-2026-18355
• CVE-2026-18453
• CVE-2026-18922
• CVE-2026-76560

References

• https://access.redhat.com/security/updates/classification/#critical