CVE-2026-105934 Apache Software Foundation CVE debrief

Who should care

Defenders managing Apache Pulsar installations, especially those with tenant admin role separation in use, should assess exposure to this vulnerability and prioritize verification and remediation efforts.

Why it matters

This vulnerability in Apache Pulsar's broker admin REST API could allow authenticated users to truncate topic partitions without proper authorization, potentially leading to data loss or corruption and elevation of privileges.

• Potential unauthorized truncation of topic partitions by authenticated users
• Possible elevation of privileges for authenticated users with limited roles
• Need for verification of broker client role configurations
• Potential data loss or corruption due to unauthorized topic truncation

Technical summary

The Apache Pulsar broker admin REST API's truncate operation for persistent topics does not correctly enforce tenant admin authorization when truncating a partitioned topic. This could allow an authenticated user to truncate partitions under certain conditions, especially if the broker's client role is a superuser or an admin of the target tenant. The vulnerability affects the broker's internal admin client, which authenticates with the broker's client credentials rather than the caller's identity. To address this, defenders should prioritize verifying exposure of Apache Pulsar installations to this vulnerability.

Defensive priority

Defenders should prioritize verifying exposure of Apache Pulsar installations to this vulnerability, especially if tenant admin role separation is in use.

Recommended defensive actions

• Verify Apache Pulsar installations for exposure to this vulnerability
• Check if tenant admin role separation is in use
• Review broker client role configurations
• Consider upgrading to a fixed version of Apache Pulsar
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Review compensating controls for exposed systems while remediation is scheduled and verified

Evidence notes

The CVE Program record and NVD vulnerability detail provide official information on the vulnerability. The Apache Pulsar security page and mailing list thread offer supplemental details. To verify exposure, defenders should review broker client role configurations and assess potential data loss or corruption due to unauthorized topic truncation. This vulnerability could allow authenticated users to truncate partitions under certain conditions, especially if tenant admin role separation is in use.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.