CVE-2026-55106: authentik: Unauthenticated LDAP directory data disclosure
authentik is an open-source identity provider. Prior to 2026.2.6 and 2026.5.5, a diagnostic action on the LDAP Source API does not enforce the object-level read-authorization filter used by the rest of the API. Any party able to reach the API, including an unauthenticated client, can invoke the diagnostic action against a configured LDAP Source. The server then connects to the upstream directory using the source's configured bind credentials and returns a bounded set of directory entries. The response exposes the distinguished names of those entries and the names of the attributes present on them, revealing directory structure, naming conventions, and the existence of specific accounts and groups, but not attribute values. Deployments without a configured LDAP Source are not affected. This issue is fixed in versions 2026.2.6 and 2026.5.5.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
authentikto a version that resolves this vulnerability.Fixed in 2026.2.6 - Upgrade
Upgrade
authentikto a version that resolves this vulnerability.Fixed in 2026.5.5
Event History
Frequently Asked Questions
Which deployments are affected?
Any deployment with a configured LDAP Source is exposed if its LDAP Source API can be reached. No authentication is required to invoke the affected diagnostic action.
What does an attacker need to exploit this?
An attacker only needs network access to the API and knowledge of, or ability to target, a configured LDAP Source. The server performs the upstream LDAP connection using that source's configured bind credentials.
What information can be disclosed?
The diagnostic response is bounded and reveals directory-entry distinguished names and the names of attributes present. It does not expose attribute values, but can disclose directory structure, naming conventions, and the existence of accounts and groups.
What versions contain the fix?
Upgrade authentik to version 2026.2.6 or 2026.5.5. Deployments without any configured LDAP Source are not affected.