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Directory ServerApplication · Redhat

CVE-2026-11611

MEDIUM · 6.5 CVSS v3.1 Published 2026-06-08
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable 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 Content Synchronization persistent search plugin allows unbounded memory growth when an authenticated client stops reading sync responses, enabling denial of service. Additional race conditions in plugin thread lifecycle can cause crashes during connection teardown or shutdown.

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 · moderate confidence

The Content Synchronization persistent search plugin in 389 Directory Server suffers from unbounded memory growth when authenticated clients stop reading sync responses, leading to denial of service. Additionally, race conditions in the plugin's thread lifecycle can cause crashes during connection teardown or server shutdown.

MitigationLimit exposure by restricting authenticated access to the directory and monitor for clients with abnormal sync behavior. Apply vendor patches or upgrade to a fixed version when available.

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/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. Identify installed Directory Server package and version
    Check if 389-ds-base or redhat-ds packages are installed (e.g., rpm -qa | grep -E '389-ds|redhat-ds'), then get version with rpm -qi or dnf info
    Affected if Version matches 11.0, 12.0, 13.0 (Redhat Directory Server) or any version of 389 Directory Server on RHEL 7.0-10.0
  2. Verify Content Synchronization plugin is enabled
    Query the cn=plugins,cn=config LDAP tree or check /etc/dirsrv/slapd-<instance>/schema/99sync.ldif for sync plugin configuration; on CLI, run dsconf <instance> plugin list and look for 'sync'
    Affected if The Content Synchronization (sync) plugin is present and enabled in the plugin configuration
  3. Confirm persistent search is in use
    Search LDAP for active persistent search controls: ldapsearch -x -D 'cn=directory manager' -W -b 'cn=monitor' '(objectClass=*)' or check connection logs for 'persistent search' entries
    Affected if Persistent search operations are actively used or configured in the directory
  4. Check for memory consumption from sync operations
    Monitor process memory (ps aux | grep ns-slapd) over time or check dsinstance/logs for growing memory indicators; inspect cn=monitor,cn=Sync,cn=plugins for pending sync responses
    Affected if Memory usage grows unbounded without client consumption or sync response queue accumulates without limit

You are affected if running a vulnerable 389 Directory Server version with the Content Synchronization persistent search plugin enabled and authenticated clients can initiate sync operations.

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

Limit exposure by restricting authenticated access to the directory and monitor for clients with abnormal sync behavior. Apply vendor patches or upgrade to a fixed version when available.

Fix this in Directory Server Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,580
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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-2026-11611 in production — separate from our analysis above.

No notes yet

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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
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