dbcve.org
Directory ServerApplication · Redhat

CVE-2026-11788

HIGH · 7.5 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The 389 Directory Server dereference control plugin fails to check for memory allocation failures before using a BER structure. When the system is under memory pressure and the allocation fails, the plugin attempts to use a NULL or invalid BER structure, causing the LDAP server to crash. An unauthenticated remote attacker can exploit this to perform denial of service attacks.

MitigationApply the vendor patch for CVE-2026-11788 to add proper allocation failure checking in the dereference control plugin. Until patched, monitor server memory availability and consider resource limits to reduce the attack surface.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Directory ServerApplication
Affected:= 11.0= 12.0= 13.0
389 Directory ServerOperating system
Affected:all versions
Enterprise LinuxOperating system
Affected:= 7.0= 8.0= 9.0= 10.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify 389 Directory Server is installed
    Run 'rpm -qa | grep -E "389-ds-base|redhat-ds-.*"' to list installed Directory Server packages, then 'rpm -q <package> --qf "%{VERSION}"' to get the exact version number
    Affected if The installed version matches 11.0, 12.0, 13.0, or is any version of Redhat 389 Directory Server (all versions affected)
  2. Confirm the OS version
    Run 'cat /etc/redhat-release' to identify the RHEL version
    Affected if The OS is RHEL 7.0, 8.0, 9.0, or 10.0 and 389 Directory Server is installed
  3. Locate the dereference plugin configuration
    Search the directory server configuration (typically in /etc/dirsrv/slapd-<instance>/dse.ldif or via ldapsearch to cn=plugins,cn=config) for 'nsslapd-pluginName: dereference' or similar dereference plugin entry
    Affected if The dereference plugin is configured and loaded on the server
  4. Check if dereference plugin is enabled
    Examine the plugin entry (cn=dereference,cn=plugins,cn=config) for the nsslapd-pluginEnabled attribute; if not present, check if the plugin is commented out in the configuration
    Affected if The dereference plugin is enabled (not disabled) in the server configuration
  5. Verify plugin library exists
    Locate the dereference plugin shared library (typically in /lib64 or /usr/lib64/dirsrv/plugins/libdedereference.so) using 'find /usr -name "*dereferen*" 2>/dev/null'
    Affected if The dereference plugin library file exists on the system

You are affected if you run any version of Redhat 389 Directory Server or Redhat Directory Server 11.0/12.0/13.0 on RHEL 7-10, and the dereference control plugin is enabled in your server configuration.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the vendor patch for CVE-2026-11788 to add proper allocation failure checking in the dereference control plugin. Until patched, monitor server memory availability and consider resource limits to reduce the attack surface.

Fix this in Directory Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-11788 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-11788 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data