CVE-2026-11789Network attack vector

Authenticated LDAP crash via SMD5 length underflow

Published Jun 9, 2026 · Updated Jun 9, 2026

Integer underflow in Red Hat 389 Directory Server allows remote authenticated users to crash the LDAP server during authentication. The SMD5 password storage plugin subtracts 16 from the length of a stored hash shorter than 16 bytes, wrapping the salt length and over-reading a buffer. Directory Manager privileges are normally required to plant the hash; with non-default nsslapd-allow-hashed-passwords enabled, a lower-privileged user can do so, and each bind to the account crashes the service again.

CVSS severity4.9
Medium
EPSS probability0.28%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer underflow in Red Hat 389 Directory Server allows remote authenticated users to crash the LDAP server during authentication. The SMD5 password storage plugin subtracts 16 from the length of a stored hash shorter than 16 bytes, wrapping the salt length and over-reading a buffer. Directory Manager privileges are normally required to plant the hash; with non-default nsslapd-allow-hashed-passwords enabled, a lower-privileged user can do so, and each bind to the account crashes the service again.

The record

CVE
CVE-2026-11789
Published
Jun 9, 2026
Updated
Jun 9, 2026
Vendor
389 Directory Server
Product
Red Hat Directory Server
Classifications
CWE-191, T1499
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jun 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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 privilegesadmin

What is affected?

389 Directory Server · Red Hat Directory ServerAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 7Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
4.9Red HatCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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