CVE-2026-44825: Apache Solr: Enabling BasicAuth using bin/solr CLI configures additional insecure users

[Jan Høydahl <janhoy () apache org>]

Severity: High 

Affected versions:

- Apache Solr (org.apache.solr:solr-core) 9.4.0 through 9.10.1
- Apache Solr (org.apache.solr:solr-core) 10.0.0

Description:

Hardcoded credentials in the Basic Authentication setup tool (bin/solr auth enable) in Apache Solr versions 9.4.0 
through 9.10.1 and 10.0.0 allows a remote attacker to gain full administrative access to the cluster via publicly known 
default credentials installed silently alongside the user-specified account. 

As an immediate workaround without upgrading, delete the template users (superadmin, admin, search, index) from 
security.json or change their passwords.
The future, not yet released, versions 9.11.0 and 10.1.0 will not be vulnerable, and it will be enough to upgrade to 
solve the issue.

Not affected:
  *  Clusters where bin/solr auth enable was not used to bootstrap BasicAuth
  *  Clusters where template users have been assigned strong passwords after bootstrap

This issue is being tracked as SOLR-18233 

Credit:

Naveen Sunkavally, Horizon3.ai (finder)

References:

https://solr.apache.org
https://www.cve.org/CVERecord?id=CVE-2026-44825
https://issues.apache.org/jira/browse/SOLR-18233