CVE-2026-63259: Kibana Authorization Bypass Vulnerability

CVE-2026-63259 Overview

CVE-2026-63259 is an authorization bypass vulnerability in Elastic Kibana that allows authenticated users to access scheduled query result data from Kibana Spaces they are not authorized to view. The flaw is classified under [CWE-639] Authorization Bypass Through User-Controlled Key, commonly known as an Insecure Direct Object Reference (IDOR). Attackers who supply crafted identifiers can reference data belonging to other Spaces, resulting in information disclosure. Elastic addressed the issue in the Kibana 9.4.4 security update tracked as ESA-2026-70.

Critical Impact
Authenticated users can retrieve scheduled query result data from Kibana Spaces outside their authorization boundary, breaking multi-tenant isolation.

Affected Products

Elastic Kibana (versions prior to 9.4.4)
Kibana deployments using Spaces for multi-tenant isolation
Environments relying on scheduled query result access controls

Discovery Timeline

2026-07-21 - CVE-2026-63259 published to NVD
2026-07-22 - Last updated in NVD database

Technical Details for CVE-2026-63259

Vulnerability Analysis

The vulnerability resides in Kibana's handling of scheduled query result identifiers. Kibana Spaces provide logical separation between dashboards, saved objects, and query artifacts across teams or tenants. The affected endpoint accepts a user-supplied identifier that references scheduled query result data. The server resolves that identifier without confirming the requester holds authorization for the Space that owns the referenced resource. As a result, an authenticated user can pass an identifier belonging to another Space and receive its result data in the response.

Root Cause

The root cause is missing authorization enforcement on a resource lookup keyed by a user-controlled parameter. The application trusts the identifier as sufficient proof of access. It skips the Space-scoped authorization check that should validate the caller against the resource owner. This is a canonical [CWE-639] pattern in which access control depends on the secrecy or predictability of an object reference rather than on an explicit permission check.

Attack Vector

Exploitation requires network access to the Kibana instance and low-privilege authenticated credentials. No user interaction is needed. An attacker with a valid Kibana account enumerates or guesses identifiers for scheduled query results and issues requests that include those identifiers. The server returns confidential query result content from Spaces the attacker cannot navigate to through the standard user interface. The impact is limited to confidentiality; integrity and availability are not affected. Refer to the Elastic Security Update ESA-2026-70 for vendor technical details.

Detection Methods for CVE-2026-63259

Indicators of Compromise

Kibana audit log entries showing a single account accessing scheduled query result identifiers associated with multiple Spaces the user is not a member of.
Elevated request volume against scheduled query result endpoints with sequential or enumerated identifier patterns.
HTTP 200 responses to scheduled query result requests originating from accounts without membership in the target Space.

Detection Strategies

Enable Kibana audit logging and alert on cross-Space object access where the actor's Space membership does not include the resource's owning Space.
Baseline normal scheduled query access patterns per user and flag deviations, particularly high-cardinality identifier access.
Correlate authentication events with subsequent scheduled query API calls to identify low-privilege accounts pivoting to sensitive result data.

Monitoring Recommendations

Ingest Kibana and Elasticsearch audit logs into a centralized SIEM for retention and correlation.
Monitor reverse proxy or load balancer logs for anomalous request rates against scheduled query result API paths.
Track privileged and service account activity separately to reduce noise while surfacing lateral access attempts.

How to Mitigate CVE-2026-63259

Immediate Actions Required

Upgrade all Kibana instances to version 9.4.4 or later as specified in ESA-2026-70.
Review audit logs for prior access to scheduled query results by accounts outside authorized Spaces.
Rotate any credentials or secrets that may have been exposed through disclosed scheduled query results.

Patch Information

Elastic released the fix in Kibana 9.4.4. Details are documented in the Elastic Security Update ESA-2026-70. Administrators should apply the update through the standard Kibana upgrade procedure and verify version alignment across all nodes.

Workarounds

Restrict network access to Kibana to trusted users and administrative networks until the patch is applied.
Reduce the number of low-privilege accounts with authenticated access to Kibana while remediation is in progress.
Audit and minimize scheduled queries containing sensitive data until the environment is upgraded.

bash

# Verify Kibana version after upgrade
curl -u <admin_user> -X GET "https://<kibana_host>:5601/api/status" \
  -H "kbn-xsrf: true" | jq '.version.number'

# Expected output: 9.4.4 or later