CVE-2026-23906

CVE-2026-23906 is a critical-severity vulnerability in Apache Druid with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

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.

Frequently asked questions

What is CVE-2026-23906?
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.
How severe is CVE-2026-23906?
CVE-2026-23906 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-23906 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (60th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-23906?
CVE-2026-23906 affects Apache Druid. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-23906?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-23906 have an EU (EUVD) identifier?
Yes. CVE-2026-23906 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-6219.
When was CVE-2026-23906 published?
CVE-2026-23906 was published on 2026-02-10 and last updated on 2026-06-17.

References

Affected products (1)

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