CVE-2026-56146: Kibana Privilege Escalation Vulnerability

CVE-2026-56146 Overview

CVE-2026-56146 is an Improper Access Control vulnerability [CWE-284] affecting Kibana's Entity Analytics Watchlist feature. A low-privileged authenticated user with read-only Security Solution access can perform write operations against watchlist data that should require elevated privileges. Under specific deployment conditions, the same user can access data beyond their authorized scope, resulting in potential information disclosure.

The vulnerability requires network access and valid low-privilege credentials, but no user interaction. Elastic addressed the issue in the Kibana 9.4.3 security update tracked as ESA-2026-58.

Critical Impact
Read-only Security Solution users can modify Entity Analytics Watchlist configuration and, in certain deployments, access data outside their authorized scope.

Affected Products

Kibana (Entity Analytics Watchlist feature)
Elastic Stack deployments using Security Solution role-based access
Kibana versions prior to 9.4.3

Discovery Timeline

2026-07-21 - CVE-2026-56146 published to NVD
2026-07-22 - Last updated in NVD database

Technical Details for CVE-2026-56146

Vulnerability Analysis

The flaw resides in Kibana's authorization enforcement for the Entity Analytics Watchlist API. Kibana's Security Solution defines granular read and write privileges, but the watchlist endpoints fail to consistently validate that the caller holds write-level authorization before performing state-changing operations. As a result, a session authenticated with read-only Security Solution privileges can invoke write paths and alter watchlist configuration.

The issue is classified under [CWE-863] Incorrect Authorization in the NVD record and described as [CWE-284] Improper Access Control in the vendor advisory. Both taxonomies describe the same underlying defect: the authorization check does not match the sensitivity of the action performed.

Root Cause

The root cause is a mismatch between the privilege model exposed in the Kibana UI and the enforcement logic on the backend API. Certain watchlist write handlers do not require the corresponding write privilege on the Security Solution feature. Additionally, in specific deployment configurations, the space and index scoping applied to watchlist queries is insufficient, allowing the endpoint to return data outside the caller's authorized scope.

Attack Vector

An attacker must hold valid credentials for a Kibana account with read-only Security Solution access. From that session, the attacker issues HTTP requests to the Entity Analytics Watchlist endpoints to modify watchlist entries or retrieve entity data. No user interaction is required, and the attack is executed over the network against the Kibana instance.

No verified proof-of-concept code is publicly available. Refer to the Elastic Security Update ESA-2026-58 for vendor technical details.

Detection Methods for CVE-2026-56146

Indicators of Compromise

Kibana audit log entries showing write operations against Entity Analytics Watchlist endpoints by users assigned only read privileges on the Security Solution feature.
Unexpected additions, deletions, or modifications of watchlist entries not correlated with an authorized administrator session.
Entity Analytics queries returning results across spaces or indices that exceed the requesting user's assigned scope.

Detection Strategies

Enable Kibana audit logging and alert on watchlist write actions where the actor's role grants only read on the Security Solution feature.
Correlate Elasticsearch and Kibana logs to identify sessions performing privileged watchlist operations without matching administrative role assignments.
Baseline normal watchlist change frequency per user and flag deviations for review.

Monitoring Recommendations

Forward Kibana and Elasticsearch audit logs to a centralized SIEM for retention and correlation.
Monitor authentication events for low-privileged Security Solution accounts that begin issuing write-type API calls.
Review role assignments periodically to ensure least-privilege alignment with the Security Solution feature privileges.

How to Mitigate CVE-2026-56146

Immediate Actions Required

Upgrade Kibana to version 9.4.3 or later, which contains the fix released as ESA-2026-58.
Audit user role assignments for the Security Solution feature and remove unnecessary Kibana access for non-analyst accounts.
Review Entity Analytics Watchlist entries for unauthorized modifications since the vulnerable version was deployed.

Patch Information

Elastic released the fix in Kibana 9.4.3. Deployment details and remediation guidance are documented in the Elastic Security Update ESA-2026-58 advisory. Elastic Cloud customers should confirm their managed deployments have been upgraded to a patched build.

Workarounds

Restrict Security Solution feature access to trusted analyst accounts only until the upgrade is applied.
Place Kibana behind a reverse proxy that restricts access to the Entity Analytics Watchlist API paths for non-administrative users.
Enable Kibana audit logging so any exploitation attempts are captured for later review.

bash

# Verify the running Kibana version and confirm it is 9.4.3 or later
curl -sk -u "$KBN_USER:$KBN_PASS" \
  "$KIBANA_URL/api/status" | jq '.version.number'

# List users assigned Security Solution privileges for review
curl -sk -u "$ES_USER:$ES_PASS" \
  "$ES_URL/_security/user" | jq '.'