CVE-2026-11788: Red Hat Directory Server 11.5 E4S for RHEL 8 · NULL Pointer Dereference
Affects Red Hat Directory Server 11.5 E4S for RHEL 8Source CVE Database V5
Not known to be exploited · CVSS 5.9 Medium.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Directory Server 11.5 E4S for RHEL 8redhat-ds:11 | Affected– | Fixed in– |
| Red Hat Directory Server 11.7 E4S for RHEL 8redhat-ds:11 | Affected– | Fixed in– |
| Red Hat Directory Server 11.9 for RHEL 8redhat-ds:11 | Affected– | Fixed in– |
| Red Hat Directory Server 12.2 E4S for RHEL 9redhat-ds:12 | Affected– | Fixed in– |
| Red Hat Directory Server 12.4 E4S for RHEL 9redhat-ds:12 | Affected– | Fixed in– |
| Red Hat Enterprise Linux 10389-ds-base | Affected– | Fixed in– |
AI-suggested
Red Hat has released an official security update fixing this vulnerability in the 389-ds-base package. Applying the update is the recommended remediation. Alternatively, disabling the deref plugin entirely removes the vulnerable code path (using 'dsconf <instance> plugin deref disable' and restarting the directory server). Disabling anonymous access (setting 'nsslapd-allow-anonymous-access=off') raises the exploitation bar from unauthenticated to authenticated. Additional defense-in-depth includes configuring memory limits (nsslapd-maxbersize, nsslapd-conntablesize) and deploying the server in a cgroup with memory constraints. Patch status is confirmed fixed in updated Red Hat packages.
Description
A flaw was found in 389 Directory Server. The dereference control plugin does not check for allocation failure before using a BER structure, allowing an unauthenticated remote attacker to crash the LDAP server when the system is under memory pressure.
References
- access.redhat.com/security/cve/CVE-2026-11788 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2485423 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55421 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55422 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55425 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55426 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55423 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55424 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55532 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55530 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55756 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55757 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55758 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55794 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56048 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56047 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:56050 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:79217 (opens in a new tab)