CVE-2026-103552: Apache Directory LDAP API: A unbound client can send a deeply nested search filter that overflows the stack in the server's decoder

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-02 · updated 2026-10-02
Weakness: CWE-121

Description

Stack Overflow vulnerability in Apache Directory LDAP API. Before binding, a client can send a deeply nested search filter that overflows the stack in the server's decoder. 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.

Affected products

Apache Software Foundation Apache Directory LDAP API: from 1.2.0 before 1.2.9 — fixed in 1.2.9

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache Directory LDAP API 1.2.9. Check the vendor advisory for mitigations.

References

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