CVE-2026-102406 Elastic CVE debrief

Who should care

Defenders responsible for Kibana deployments, particularly those using Fleet package management, should assess their exposure and verify their instances to prevent potential data interception.

Why it matters

Defenders should prioritize verifying and updating Kibana instances to prevent potential data interception. The vulnerability allows a user with delegated Fleet package-management privileges to claim a data stream identifier already in use by another tenant, potentially leading to cross-tenant data interception.

• Potential data interception and unauthorized disclosure
• Possible modification of ingested data
• Prevention of data from reaching its intended destination
• Need for verification and updates to prevent exploitation

Technical summary

The vulnerability exists in Kibana's Fleet package installation process, allowing a user with delegated Fleet package-management privileges to claim a data stream identifier already in use by another tenant. This could lead to cross-tenant data interception, exposing the affected tenant's subsequently ingested data to unauthorized disclosure and modification. The issue arises from the lack of verification of ownership for the data stream identifier before applying the uploaded package's generated index and ingest-pipeline settings to existing infrastructure. As a result, an attacker could redirect an existing tenant's data stream through infrastructure under their control, leading to potential data interception

Defensive priority

Defenders should prioritize verifying and updating Kibana instances to prevent potential data interception. Specifically, review Fleet package installations and verify data stream identifiers to ensure they are not being misused.

Recommended defensive actions

• Verify and update Kibana instances to the latest version
• Review Fleet package installations and data stream identifiers
• Monitor for suspicious activity related to data streams and tenant infrastructure
• Confirm whether affected Kibana 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 CVE record and source item provide details on the vulnerability, including its description, affected versions, and potential impact. However, additional information on exploitation or affected systems is limited.

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.