Apache Druid: Improper Authentication
CVE-2026-23906 is a critical-severity improper authentication vulnerability in Apache Druid from Apache, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 36.0.0 as the first without the flaw, so updating Apache Druid to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.07% chance of exploitation within 30 days, higher than 65% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Apache Druid to 36.0.0 or a later version.
- Update Druid to 36.0.0 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache Druid | 0.17.0 up to, but not including, 36.0.0 | 36.0.0 |
| Apache | Druid | 0.17.0 up to, but not including, 36.0.0 | 36.0.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in Apache Druid
- 9.8 Critical severity
Recent Improper Authentication vulnerabilities
- 7.3 High severity
- 9.8 Critical severity
- 9.1 Critical severity
- 8.8 High severity
- 7.5 High severity
- 9.6 Critical severity
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