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Vulnerability · Published Sep 7, 2026 · Assigned by redhat

CVE-2026-18453389-ds-base: 389-ds-base: pre-authentication null pointer dereference via paged results and use_one_backend control in op_shared_search

High 7.5

In plain English

A high-severity null pointer dereference in Red Hat Directory Server 11.5 E4S for RHEL 8 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 58% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.8%top 41.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:10389-ds-base3.2.0-10.el10_2ALSA-2026:64785
AlmaLinux:8389-ds-base1.4.3.39-28.module_el8.10.0+4274+00f9a3f1ALSA-2026:64791
AlmaLinux:9389-ds-base2.8.0-10.el9_8ALSA-2026:64784
AlmaLinux:10389-ds-base-bdb3.2.0-10.el10_2ALSA-2026:64785
AlmaLinux:10389-ds-base-devel3.2.0-10.el10_2ALSA-2026:64785
AlmaLinux:8389-ds-base-devel1.4.3.39-28.module_el8.10.0+4274+00f9a3f1ALSA-2026:64791
AlmaLinux:9389-ds-base-devel2.8.0-10.el9_8ALSA-2026:64784
AlmaLinux:8389-ds-base-legacy-tools1.4.3.39-28.module_el8.10.0+4274+00f9a3f1ALSA-2026:64791
AlmaLinux:10389-ds-base-libs3.2.0-10.el10_2ALSA-2026:64785
AlmaLinux:8389-ds-base-libs1.4.3.39-28.module_el8.10.0+4274+00f9a3f1ALSA-2026:64791
AlmaLinux:9389-ds-base-libs2.8.0-10.el9_8ALSA-2026:64784
AlmaLinux:10389-ds-base-snmp3.2.0-10.el10_2ALSA-2026:64785
AlmaLinux:8389-ds-base-snmp1.4.3.39-28.module_el8.10.0+4274+00f9a3f1ALSA-2026:64791
AlmaLinux:9389-ds-base-snmp2.8.0-10.el9_8ALSA-2026:64784
AlmaLinux:10python3-lib3893.2.0-10.el10_2ALSA-2026:64785
AlmaLinux:8python3-lib3891.4.3.39-28.module_el8.10.0+4274+00f9a3f1ALSA-2026:64791
AlmaLinux:9python3-lib3892.8.0-10.el9_8ALSA-2026:64784
Debian:12389-ds-baseno fix listedDEBIAN-CVE-2026-18453
Debian:13389-ds-baseno fix listedDEBIAN-CVE-2026-18453
Rocky Linux:10389-ds-base0:3.2.0-10.el10_2RLSA-2026:64785
Rocky Linux:8389-ds-base0:1.4.3.39-28.module+el8.10.0+40311+cd962df1RLSA-2026:64791
Rocky Linux:9389-ds-base0:2.8.0-10.el9_8RLSA-2026:64784
Ubuntu:22.04:LTS389-ds-baseno fix listedUBUNTU-CVE-2026-18453
Ubuntu:24.04:LTS389-ds-baseno fix listedUBUNTU-CVE-2026-18453
Ubuntu:26.04:LTS389-ds-baseno fix listedUBUNTU-CVE-2026-18453
Ubuntu:26.10389-ds-baseno fix listedUBUNTU-CVE-2026-18453

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Directory Server 11.5 E4S for RHEL 8 see references
Red Hat Red Hat Directory Server 11.7 E4S for RHEL 8 see references
Red Hat Red Hat Directory Server 11.9 for RHEL 8 see references
Red Hat Red Hat Directory Server 12.2 E4S for RHEL 9 see references
Red Hat Red Hat Directory Server 12.4 E4S for RHEL 9 see references
Red Hat Red Hat Enterprise Linux 10 see references
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support see references
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support see references
Red Hat Red Hat Enterprise Linux 8 see references
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support see references
Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On see references
Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support see references
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On see references
Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service see references
Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9 see references
Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions see references
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support see references
Red Hat Red Hat Directory Server 13.2 see references
Red Hat Red Hat Directory Server 12 see references
Red Hat Red Hat Directory Server 13 see references
Red Hat Red Hat Enterprise Linux 6 see references

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References