Unauthenticated service interruption via unbounded LDAP controls
Published May 20, 2026 · Updated May 20, 2026
Resource exhaustion in 389-ds-base allows remote attackers to interrupt LDAP service with crafted requests before authentication. The get_ldapmessage_controls_ext() loop allocates a structure for every LDAP control and repeatedly expands its pointer list without limiting the control count. Hundreds of thousands of controls fit within the default 2 MB BER limit; concurrent requests cause latency, worker starvation, or out-of-memory termination.
Summary
What happened
Resource exhaustion in 389-ds-base allows remote attackers to interrupt LDAP service with crafted requests before authentication. The get_ldapmessage_controls_ext() loop allocates a structure for every LDAP control and repeatedly expands its pointer list without limiting the control count. Hundreds of thousands of controls fit within the default 2 MB BER limit; concurrent requests cause latency, worker starvation, or out-of-memory termination.
The record
- CVE
- CVE-2026-9064
- Published
- May 20, 2026
- Updated
- May 20, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Directory Server
- Classifications
- CWE-770, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 20, 2026CVE publishedPublication date reported by the CVE source.
- May 20, 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?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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