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

HIGH
7.5
CVSS Score
Published: September 7, 2026 at 02:14 PM UTC
Updated: October 8, 2026 at 03:17 PM UTC
1 product affected across 1 vendorDirectory Server

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Severity
HIGH7.5
Exploit prediction
EPSS 0.8%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versions12
Vendor states this is fixed in 13 (unaffected)
Vendor states this is fixed in 1788851765 (unaffected)
Vendor states this is fixed in 8060020260908152739.0ca98e7e (unaffected)
Vendor states this is fixed in 8080020260903102346.f969626e (unaffected)
Vendor states this is fixed in 8100020260904171440.37ed7c03 (unaffected)
Vendor states this is fixed in 9020020260903155914.1674d574 (unaffected)
Vendor states this is fixed in 9040020260903102623.1674d574 (unaffected)

References (19)

VDB Entryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-18453
Issue Trackingx_refsource_REDHAT
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2509696
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:64771
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:64776
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:64778
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:64779
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:64781
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:64789

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHredhat
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-476

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