CVE-2026-78582 Overview
CVE-2026-78582 is a missing authorization vulnerability [CWE-862] in Elastic Kibana. An authenticated user with Synthetics privileges scoped to one Kibana space can permanently delete Synthetics monitors shared into spaces they do not have access to. When the monitor is bound to a private location, the delete operation also removes the underlying Elastic Agent integration configuration. The destructive path bypasses the authorization checks Fleet would normally enforce. Elastic published fixes in Kibana 8.19.22, 9.4.7, and 9.5.3 under advisory ESA-2026-139.
Critical Impact
A low-privileged, space-scoped Synthetics user can delete monitors and Fleet-managed Elastic Agent integrations across spaces they should not reach, causing loss of monitoring coverage and integration state.
Affected Products
- Elastic Kibana 8.x prior to 8.19.22
- Elastic Kibana 9.4.x prior to 9.4.7
- Elastic Kibana 9.5.x prior to 9.5.3
Discovery Timeline
- 2026-09-26 - CVE-2026-78582 published to the National Vulnerability Database
- 2026-09-28 - CVE-2026-78582 record last modified in NVD
Technical Details for CVE-2026-78582
Vulnerability Analysis
The flaw sits in the Synthetics monitor deletion workflow within Kibana. Kibana spaces are intended to isolate saved objects and privileges across teams. Synthetics monitors can be shared into multiple spaces, but the delete endpoint does not verify that the caller holds Synthetics privileges in every space the monitor is shared into. A user authorized in a single space can therefore issue a delete request that removes the monitor globally.
The secondary impact targets Fleet. Synthetics monitors associated with a private location are backed by an Elastic Agent integration policy. Deleting the monitor cascades into the integration configuration without routing through Fleet's own authorization layer. The attacker never needs Fleet privileges to destroy the integration state.
Root Cause
The root cause is a missing authorization check (CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels). The Synthetics delete handler evaluates the caller's privileges only against the current space, not against every space containing the shared monitor. The cascading Fleet operation inherits the Synthetics caller context instead of enforcing an independent Fleet authorization decision.
Attack Vector
Exploitation requires an authenticated Kibana session with Synthetics privileges scoped to any single space. The attacker identifies a monitor shared into other spaces and submits a delete request through the Synthetics API or UI. Kibana removes the monitor from all spaces and, where a private location is involved, deletes the backing Elastic Agent integration. No user interaction from victims is required. See the Elastic Security Update ESA-2026-139 for vendor technical details.
Detection Methods for CVE-2026-78582
Indicators of Compromise
- Unexpected Synthetics monitor deletion audit events originating from users whose role mappings restrict them to a single Kibana space.
- Fleet integration policy deletion events that are not preceded by an authorized Fleet administrator action.
- Gaps in Synthetics monitoring data or disappearance of private-location monitors without a corresponding change request.
Detection Strategies
- Enable Kibana audit logging and alert on saved_object_delete events for the synthetics-monitor type correlated with the actor's space scope.
- Correlate Synthetics delete events with Fleet agent_policy and package_policy delete events sharing the same request ID or actor.
- Baseline normal Synthetics administrators and flag deletions issued by any identity outside that set.
Monitoring Recommendations
- Forward Kibana and Elasticsearch audit logs to a centralized analytics pipeline for cross-space correlation.
- Monitor the Synthetics monitor inventory count per space and alert on sudden decreases.
- Review Elastic Agent integration policy change history on a scheduled cadence to catch unauthorized removals.
How to Mitigate CVE-2026-78582
Immediate Actions Required
- Upgrade Kibana to 8.19.22, 9.4.7, or 9.5.3 or later as published in ESA-2026-139.
- Audit existing role mappings and remove Synthetics privileges from users who do not require them.
- Inventory Synthetics monitors shared across multiple spaces and confirm their current state after upgrade.
Patch Information
Elastic resolved CVE-2026-78582 in Kibana versions 8.19.22, 9.4.7, and 9.5.3. Full remediation details are published in the Elastic Security Update ESA-2026-139. Apply the upgrade through your standard Elastic Stack maintenance process and validate Kibana and Fleet health after deployment.
Workarounds
- Restrict Synthetics privileges to trusted administrators until the patch is applied.
- Avoid sharing Synthetics monitors across spaces where privilege boundaries differ between tenants.
- Enable Kibana audit logging to retain forensic evidence of any unauthorized deletions during the exposure window.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.