CVE-2026-62391 Apache Software Foundation CVE debrief

Who should care

Apache Kyuubi users and administrators, as well as security teams and vulnerability management teams responsible for reviewing and mitigating potential security risks in their environments, should prioritize upgrading to version 1.12.0 and review server-side configs to prevent potential security breaches. They should also monitor for unusual activity in Apache Kyuubi Server and confirm whether affected Apache Kyuubi deployments exist in managed environments.

Technical summary

The security fix for CVE-2025-66518 is incomplete, allowing clients to bypass server-side config kyuubi.session.local.dir.allowlist via unprefixed Spark config aliases. This issue affects Apache Kyuubi from version 1.6.0 before 1.12.0. Users are recommended to upgrade to version 1.12.0, which fixes the issue. The vulnerability can be mitigated by reviewing server-side configs and monitoring for unusual activity in Apache Kyuubi Server.

Defensive priority

Apache Kyuubi users should prioritize upgrading to version 1.12.0.

Recommended defensive actions

• Upgrade Apache Kyuubi to version 1.12.0
• Review and adjust server-side config kyuubi.session.local.dir.allowlist
• Monitor for unusual activity in Apache Kyuubi Server
• Confirm whether affected Apache Kyuubi deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The security fix for CVE-2025-66518 is incomplete, allowing clients to bypass server-side config kyuubi.session.local.dir.allowlist via unprefixed Spark config aliases. This issue affects Apache Kyuubi from 1.6.0 before 1.12.0. Evidence is limited to CVE and NVD details. Defenders should verify affected Kyuubi deployments, review server-side configs, and monitor for unusual activity.

Official resources