CVE-2026-23906: apache software foundation apache druid Improper Authentication

Vulnerability summary

CVE-2026-23906 is a critical (CVSS 9.8) Improper Authentication vulnerability in apache software foundation apache druid. EPSS estimates a 1.13% chance of exploitation in the next 30 days, higher than 65.9% of scored vulnerabilities.

Timeline

1. 10-02-2026
   PublishedVulnerability first disclosed.
2. 12-02-2026
   Last modifiedVulnerability information updated.

Description

Affected Products and Versions * Apache Druid * Affected Versions: 0.17.0 through 35.x (all versions prior to 36.0.0) * Prerequisites: * druid-basic-security extension enabled * LDAP authenticator configured * Underlying LDAP server permits anonymous bind Vulnerability Description An authentication bypass vulnerability exists in Apache Druid when using the druid-basic-security extension with LDAP authentication. If the underlying LDAP server is configured to allow anonymous binds, an attacker can bypass authentication by providing an existing username with an empty password. This allows unauthorized access to otherwise restricted Druid resources without valid credentials. The vulnerability stems from improper validation of LDAP authentication responses when anonymous binds are permitted, effectively treating anonymous bind success as valid user authentication. Impact A remote, unauthenticated attacker can: * Gain unauthorized access to the Apache Druid cluster * Access sensitive data stored in Druid datasources * Execute queries and potentially manipulate data * Access administrative interfaces if the bypassed account has elevated privileges * Completely compromise the confidentiality, integrity, and availability of the Druid deployment Mitigation Immediate Mitigation (No Druid Upgrade Required): * Disable anonymous bind on your LDAP server. This prevents the vulnerability from being exploitable and is the recommended immediate action. Resolution * Upgrade Apache Druid to version 36.0.0 or later, which includes fixes to properly reject anonymous LDAP bind attempts.

• CWE-287Improper AuthenticationWhen an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.