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

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-07 · updated 2026-10-08
Weakness: CWE-476

Description

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.

Affected products

Red Hat Directory Server 11.5 E4S for RHEL 8: all versions — fixed in 8060020260908152739.0ca98e7e
Red Hat Directory Server 11.7 E4S for RHEL 8: all versions — fixed in 8080020260903102346.f969626e
Red Hat Directory Server 11.9 for RHEL 8: all versions — fixed in 8100020260904171440.37ed7c03
Red Hat Directory Server 12: all versions
Red Hat Directory Server 12.2 E4S for RHEL 9: all versions — fixed in 9020020260903155914.1674d574
Red Hat Directory Server 12.4 E4S for RHEL 9: all versions — fixed in 9040020260903102623.1674d574
Red Hat Directory Server 13.2: all versions — fixed in 1788851765
Red Hat Enterprise Linux 10: all versions — fixed in 0:3.2.0-10.el10_2
Red Hat Enterprise Linux 10.0 Extended Update Support: all versions — fixed in 0:3.0.6-21.el10_0
Red Hat Enterprise Linux 7 Extended Lifecycle Support: all versions — fixed in 0:1.3.11.1-15.el7_9
Red Hat Enterprise Linux 8: all versions — fixed in 8100020260904155442.25e700aa
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: all versions — fixed in 8040020260901171549.96015a92
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: all versions — fixed in 8040020260901171549.96015a92
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: all versions — fixed in 8060020260901145727.824efc52
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: all versions — fixed in 8060020260901145727.824efc52
Red Hat Enterprise Linux 8.8 Telecommunications Update Service: all versions — fixed in 8080020260831180218.6dbb3803
Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions: all versions — fixed in 8080020260831180218.6dbb3803
Red Hat Enterprise Linux 9: all versions — fixed in 0:2.8.0-10.el9_8
Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions: all versions — fixed in 0:2.2.4-22.el9_2
Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions: all versions — fixed in 0:2.4.5-29.el9_4
Red Hat Enterprise Linux 9.6 Extended Update Support: all versions — fixed in 0:2.6.1-24.el9_6

How to fix

Upgrade to a fixed version: Red Hat Directory Server 11.5 E4S for RHEL 8 8060020260908152739.0ca98e7e; Red Hat Directory Server 11.7 E4S for RHEL 8 8080020260903102346.f969626e; Red Hat Directory Server 11.9 for RHEL 8 8100020260904171440.37ed7c03; Red Hat Directory Server 12.2 E4S for RHEL 9 9020020260903155914.1674d574; Red Hat Directory Server 12.4 E4S for RHEL 9 9040020260903102623.1674d574; Red Hat Directory Server 13.2 1788851765; Red Hat Enterprise Linux 10 0:3.2.0-10.el10_2; Red Hat Enterprise Linux 10.0 Extended Update Support 0:3.0.6-21.el10_0; Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:1.3.11.1-15.el7_9; Red Hat Enterprise Linux 8 8100020260904155442.25e700aa; Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support 8040020260901171549.96015a92; Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On 8040020260901171549.96015a92. Check the vendor advisory for mitigations.

References

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