CVE-2026-78582: 
Kibana vulnerability analysis and mitigation

CVE-2026-78582 is a Missing Authorization vulnerability (CWE-862) in Elastic Kibana that allows authenticated users with Synthetics privileges to permanently delete Synthetics monitors outside their authorized Kibana spaces. Affected versions span Kibana 7.12.0–7.17.29, 8.0.0–8.19.21, 9.0.0–9.4.6, and 9.5.0–9.5.2. The vulnerability was published on September 26, 2026, with patches released the same day. It carries a CVSS v3.1 base score of 6.5 (Medium) (GitHub Advisory, Elastic Advisory).

The root cause is a missing authorization check (CWE-862) in Kibana's Synthetics monitor deletion logic, classified under CAPEC-180 (Exploiting Incorrectly Configured Access Control Security Levels). When a Synthetics user scoped to a single Kibana space issues a delete request for a monitor shared into other spaces, Kibana fails to verify whether the requesting user has access to those target spaces. Additionally, when the monitor is associated with a private location, the deletion cascades to destroy the underlying Elastic Agent integration configuration in Fleet — bypassing the authorization checks that Fleet would normally enforce. The attack vector is network-based, requires low privileges (an authenticated Synthetics user), and no user interaction (GitHub Advisory, Elastic Advisory).

Successful exploitation allows an authenticated attacker to permanently delete Synthetics monitors shared across Kibana spaces they are not authorized to access, resulting in a high integrity impact with no confidentiality or availability impact per the CVSS scoring. When affected monitors are linked to private locations, the attack also destroys the associated Elastic Agent integration configuration in Fleet without proper authorization, potentially disrupting monitoring infrastructure across the organization. This could blind security and operations teams by eliminating synthetic monitoring coverage and corrupting Fleet-managed agent configurations (GitHub Advisory, Elastic Advisory).

There is no known public proof-of-concept exploit and no evidence of in-the-wild exploitation at this time (GitHub Advisory). The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.184% (7th percentile), indicating a low near-term exploitation probability. NVD's supplemental data classifies the exploitation status as "none" and the attack as non-automatable, requiring a low-privileged authenticated user to execute.

1. Obtain Synthetics Privileges: Gain or compromise an account with Synthetics privileges scoped to at least one Kibana space (e.g., through credential theft or insider access).
2. Enumerate Shared Monitors: Use the Kibana Synthetics API or UI to identify Synthetics monitors that are shared into spaces beyond the attacker's authorized space.
3. Issue Unauthorized Delete Request: Send a DELETE API request targeting a monitor ID that belongs to a space the attacker does not have access to. Kibana fails to validate cross-space authorization before processing the deletion.
4. Destroy Fleet Agent Configuration (Optional): If the targeted monitor is associated with a private location, the deletion also triggers removal of the underlying Elastic Agent integration configuration in Fleet without Fleet's normal authorization checks, amplifying the destructive impact.
5. Achieve Objective: Monitoring coverage is permanently eliminated for the targeted spaces, and Fleet configurations may be corrupted, potentially blinding operations or security teams (GitHub Advisory, Elastic Advisory).

• Logs: Kibana audit logs showing DELETE requests to Synthetics monitor endpoints (e.g., /api/synthetics/monitors/{monitorId}) from users whose assigned space does not match the monitor's owning space; Fleet audit logs showing integration configuration deletions not initiated by Fleet-authorized users.
• Application Behavior: Unexpected disappearance of Synthetics monitors from spaces where no authorized user performed a deletion; Elastic Agent integrations in Fleet removed without corresponding Fleet user activity.
• Network: API calls to Kibana Synthetics DELETE endpoints originating from accounts with limited space scope, particularly targeting monitor IDs associated with other spaces.

Elastic has released patched versions addressing this vulnerability: 7.17.30, 8.19.22, 9.4.7, and 9.5.3. Organizations should upgrade to one of these versions as the primary remediation (Elastic Advisory). As interim mitigations, administrators should review and restrict Synthetics privileges to only trusted users, audit existing Synthetics monitor configurations and cross-space sharing settings, and monitor Kibana audit logs for unauthorized deletion activity. Limiting the number of users with Synthetics privileges reduces the attack surface until patching is complete.

Elastic disclosed the vulnerability via their security advisory forum (ESA-2026-139) on September 26, 2026, alongside patches for multiple Kibana versions (Elastic Advisory). Security media noted the broader context of Elastic patching 11+ security flaws in Elasticsearch and Kibana in this release cycle, including higher-severity privilege escalation bugs (Undercode News). Qualys and Tenable both published detection plugins for this CVE shortly after disclosure, indicating standard industry response without notable alarm given the medium severity rating.