NULL pointer dereference in Red Hat Directory Server 11
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.008 (57.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 57.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000
Affected products
Weakness classification (CWE)
References
- access.redhat.com/security/cve/CVE-2026-18453 (vdb-entry)
- bugzilla.redhat.com/show_bug.cgi (issue-tracking)
- access.redhat.com/errata/RHSA-2026:64771 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64776 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64778 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64779 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64781 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64789 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64792 (vendor-advisory)
- access.redhat.com/errata/RHSA-2026:64783 (vendor-advisory)
Frequently asked questions
- What is CVE-2026-18453?
- CVE-2026-18453 is a high-severity vulnerability in Red Hat Directory Server 11, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2026-09-07.
- How severe is CVE-2026-18453?
- High severity. CVSS v3 base score is 7.5 out of 10.