: 389-ds-base-1.4.3.39-28.module+el8+2044+8274218c

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() [rhel-8.10.z] (JIRA:RHEL-244463)
* fix breaks replication total init when nsDS5ReplicaBindDNGroup is set after agreement creation [rhel-8.10.z] (JIRA:RHEL-248762)

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.

CVE-2026-18355
A heap buffer overflow flaw was found in the SASL I/O layer of 389 Directory Server (389-ds-base). In sasl_io_start_packet(), the wrapped-record length read from the wire is validated only against an upper bound. A small wire length (0, 1, or 2) produces an encrypted_buffer_count below the already-consumed encrypted_buffer_offset, causing an unsigned subtraction underflow in sasl_io_read_packet(). PR_Recv is then requested to read approximately 4 GiB into a 1024-byte heap buffer, resulting in a heap buffer overflow with attacker-controlled content. After a successful SASL bind with integrity protection (SSF > 0), a remote authenticated attacker can cause a denial of service or potentially achieve remote code execution. This flaw is distinct from CVE-2026-11774, whose fix only guards against upper-bound overflow.
CVE-2026-18453
A flaw was found in 389 Directory Server. A missing NULL pointer check in the paged results handling of op_shared_search allows an unauthenticated remote attacker to crash the LDAP server by sending a crafted sequence of search requests using the USE_ONE_BACKEND control, resulting in denial of service.
CVE-2026-18922
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.
CVE-2026-76560
A flaw was found in 389 Directory Server. The SELFDN ACI bind-rule evaluator incorrectly matches an anonymous LDAP client's empty bind DN against an empty stored attribute value, allowing an unauthenticated client to satisfy access control checks intended to require a matching authenticated identity. This can allow an anonymous LDAP client to perform an operation, such as adding or modifying a directory entry, that a SELFDN-based ACI intended to restrict to a specific authenticated user.

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