Apache Directory LDAP API flaw can consume CPU indefinitely
An advisory published on the oss-sec mailing list on October 2, 2026 warns that malformed telephone numbers can keep one CPU core busy indefinitely in Apache Directory LDAP API versions earlier than 2.1.9.
Source: CVE-2026-103885: Apache Directory LDAP API permite negação de serviço por números de telefone manipulados (seclists.org). Text prepared with AI from this source.
What happened and what to do
The advisory published on the oss-sec mailing list on October 2, 2026 rates an asymmetric resource-consumption vulnerability in Apache Directory LDAP API as important. Affected versions range from 2.1.0 to releases before 2.1.9. When processing certain malformed telephone numbers, an LDAP server using the API may keep one CPU core at 100% indefinitely. The recommendation is to upgrade to version 2.1.9.
Companies using the API should identify deployed versions and LDAP services that include it, prioritize the upgrade, and monitor CPU usage and processing errors. They can also review input validation and set alerts for persistent spikes, with response procedures to reduce the risk of service disruption.
How the consultancy can help
Wendelmaques can diagnose where the API and affected versions are used, define the scope, and implement the upgrade, input validation, and CPU and error monitoring, with support for operating the solution.
Next step
Send a short description of your LDAP services and the environment using the API to receive a proposal with a defined scope.
Let's assess your project
I reply with scope and a proposal.