CVE-2026-86344Network attack vectorHinoki check available

Unauthenticated LDAP outage via worker-thread pool exhaustion

Published Oct 1, 2026 · Updated Oct 1, 2026

Denial of service in 389-ds-base on Red Hat Directory Server and Red Hat Enterprise Linux allows remote attackers to stall LDAP service via partial messages. A completed LDAP operation followed by an incomplete LDAPMessage requeues the connection before its result is flushed; another worker waits for the I/O timeout while holding the connection mutex. With access to the LDAP listener, attackers can occupy the configured worker pool and prevent both anonymous and authenticated clients from receiving service while the connections remain open.

CVSS severityUnavailable
Unscored
EPSS probability0.35%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Denial of service in 389-ds-base on Red Hat Directory Server and Red Hat Enterprise Linux allows remote attackers to stall LDAP service via partial messages. A completed LDAP operation followed by an incomplete LDAPMessage requeues the connection before its result is flushed; another worker waits for the I/O timeout while holding the connection mutex. With access to the LDAP listener, attackers can occupy the configured worker pool and prevent both anonymous and authenticated clients from receiving service while the connections remain open.

The record

CVE
CVE-2026-86344
Published
Oct 1, 2026
Updated
Oct 1, 2026
Vendor
libuser Project
Product
Red Hat Directory Server
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

libuser Project · Red Hat Directory ServerAffected versions are unavailable in this record.
libuser Project · Red Hat Enterprise LinuxAffected versions are unavailable in this record.

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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