High severity · published Sep 7, 2026
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
7.5
CVSS
0.8%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 58% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Directory Server 11.5 E4S for RHEL 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Directory Server 11.7 E4S for RHEL 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Directory Server 11.9 for RHEL 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Directory Server 12 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Directory Server 12.2 E4S for RHEL 9 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Directory Server 12.4 E4S for RHEL 9 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Directory Server 13.2 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 6 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 7 Extended Lifecycle Support · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: vendor
Affected product
RH
Red Hat Directory Server 11.5 E4S for RHEL 8
Red Hat
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-18453
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-18453
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:64771
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:64776
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:64778
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:64779
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:64780
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:64781
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