CVE-2026-18453
High
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.
SeverityHigh
CVSS7.5
Exploit probability—
Product
Directory Server E4s 11.5
PublishedSep 7, 2026
First seenSep 7, 2026
Weakness typeCWE-476NULL pointer dereference
How to fix
Vendor advisories
- access.redhat.com/errata/RHSA-2026:64771
- access.redhat.com/errata/RHSA-2026:64776
- access.redhat.com/errata/RHSA-2026:64778
- access.redhat.com/errata/RHSA-2026:64779
- access.redhat.com/errata/RHSA-2026:64780
- access.redhat.com/errata/RHSA-2026:64781
- access.redhat.com/errata/RHSA-2026:64783
- access.redhat.com/errata/RHSA-2026:64784
- access.redhat.com/errata/RHSA-2026:64785
- access.redhat.com/errata/RHSA-2026:64789
- access.redhat.com/errata/RHSA-2026:64790
- access.redhat.com/errata/RHSA-2026:64791
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| directory_server_e4s 11.5 | No range specified | — |
| directory_server_e4s 11.7 | No range specified | — |
| directory_server 11.9 | No range specified | — |
| directory_server_e4s 12.2 | No range specified | — |
| directory_server_e4s 12.4 | No range specified | — |
| Red Hat Red Hat Enterprise Linux 10 | No range specified | — |
| Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support | No range specified | — |
| Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support | No range specified | — |
| enterprise_linux 8 | No range specified | — |
| rhel_aus 8.4 | No range specified | — |
| rhel_aus 8.6 | No range specified | — |
| rhel_e4s 8.8 | No range specified | — |
| enterprise_linux 9 | No range specified | — |
| rhel_e4s 9.2 | No range specified | — |
| rhel_e4s 9.4 | No range specified | — |
| rhel_eus 9.6 | No range specified | — |
| directory_server 13.2 | No range specified | — |
| Red Hat Red Hat Directory Server 12 | No range specified | — |
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