CVE-2026-103880: Apache Directory LDAP API: Denial of service via excessive bcrypt cost factor in stored passwords

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-02 · updated 2026-10-05
Weakness: CWE-405

Description

Asymmetric Resource Consumption vulnerability in Apache Directory LDAP API. Storing a password using the bcrypt algorithm with a high force like 30 in a LDAP server that supports this algorithm will cause the server CPU to run for hours checking the credentials. A bounded cost should be enforced to avoid a server DOS. This issue affects Apache Directory LDAP API: from 2.1.0 before 2.1.9. Users are recommended to upgrade to version 2.1.9, which fixes the issue.

Affected products

Apache Software Foundation Apache Directory LDAP API: from 2.1.0 before 2.1.9 — fixed in 2.1.9

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache Directory LDAP API 2.1.9. Check the vendor advisory for mitigations.

References

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