Description
Memory allocation with excessive size value vulnerability in Apache Directory LDAP API.



A malicious peer (or a MITM) can send a small BER-encoded response causing a large memory allocation before any data is received. This can lead to an OutOfMemoryError and denial of service.



The client JVM OOMs (OutOfMemoryError bypasses the DecoderException handlers) or pins the large allocation per connection while the attacker stalls.



A handful of connections exhausts any heap. The same bytes from an unauthenticated pre-bind client hit any embedding server that did not set MAX_PDU_SIZE_ATTR.



This issue affects Apache Directory LDAP API: from 1.2.0 before 1.2.9.



Users are recommended to upgrade to version 1.2.9, which fixes the issue.
Published: 2026-10-02
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Fri, 02 Oct 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache directory Ldap Api
Vendors & Products Apache
Apache directory Ldap Api

Fri, 02 Oct 2026 09:30:00 +0000

Type Values Removed Values Added
Description Memory allocation with excessive size value vulnerability in Apache Directory LDAP API. A malicious peer (or a MITM) can send a small BER-encoded response causing a large memory allocation before any data is received. This can lead to an OutOfMemoryError and denial of service. The client JVM OOMs (OutOfMemoryError bypasses the DecoderException handlers) or pins the large allocation per connection while the attacker stalls. A handful of connections exhausts any heap. The same bytes from an unauthenticated pre-bind client hit any embedding server that did not set MAX_PDU_SIZE_ATTR. This issue affects Apache Directory LDAP API: from 1.2.0 before 1.2.9. Users are recommended to upgrade to version 1.2.9, which fixes the issue.
Title Apache Directory LDAP API: Denial of service via excessive memory allocation in BER decode
Weaknesses CWE-789
References

Subscriptions

Apache Directory Ldap Api
cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-10-02T09:22:00.813Z

Reserved: 2026-09-29T16:17:56.332Z

Link: CVE-2026-102731

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-02T10:17:04.530

Modified: 2026-10-02T10:17:04.530

Link: CVE-2026-102731

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-02T10:30:07Z

Weaknesses