CVE-2026-76394: Splunk AI Toolkit Auth Bypass Flaw

CVE-2026-76394 Overview

CVE-2026-76394 is a missing authorization vulnerability [CWE-862] in Splunk AI Toolkit versions below 6.0.0. Multiple Representational State Transfer (REST) API handlers in the toolkit fail to enforce authorization checks. A low-privileged authenticated user without the admin or power Splunk roles can start, stop, and configure containers. The same user can read or modify connection and configuration data through the exposed REST endpoints. The flaw enables lateral impact on integrity and availability of machine learning workloads managed by the toolkit.

Critical Impact
Authenticated low-privileged users can control containers and modify sensitive configuration data via unauthenticated REST API handlers in Splunk AI Toolkit.

Affected Products

Splunk AI Toolkit versions below 6.0.0
Splunk deployments with the AI Toolkit app installed
Splunk Machine Learning Toolkit environments using AI Toolkit components

Discovery Timeline

2026-08-19 - CVE-2026-76394 published to NVD
2026-08-20 - Last updated in NVD database

Technical Details for CVE-2026-76394

Vulnerability Analysis

The vulnerability resides in the REST API layer of Splunk AI Toolkit. Multiple handlers accept requests from any authenticated Splunk user without verifying role membership. Splunk's role-based access control expects sensitive management endpoints to be restricted to admin or power roles. The affected handlers skip this check entirely, allowing any authenticated session to invoke privileged operations.

Successful exploitation lets an attacker start or stop containers used by machine learning workflows. The attacker can also read connection strings and modify toolkit configuration. This produces high integrity and availability impact on ML pipelines, while confidentiality impact is limited to configuration data reachable via the exposed handlers.

Root Cause

The root cause is missing authorization enforcement [CWE-862] in REST API handler implementations. Handlers rely on authentication alone and do not consult the caller's Splunk role before executing privileged actions. The design assumes callers are trusted once authenticated, which violates least-privilege principles for a multi-tenant platform.

Attack Vector

The attack vector is network-based and requires valid low-privileged Splunk credentials. An attacker authenticates to the Splunk instance using any standard user account. The attacker then issues HTTP requests directly to the vulnerable REST endpoints exposed by the AI Toolkit app. Because authorization checks are absent, the server processes container-management and configuration operations as if the caller held elevated roles. No user interaction is required and attack complexity is low. See the Splunk Security Advisory SVD-2026-0808 for technical details.

Detection Methods for CVE-2026-76394

Indicators of Compromise

REST API calls to AI Toolkit endpoints originating from user accounts that lack the admin or power role
Unexpected container start, stop, or reconfiguration events in Splunk AI Toolkit audit logs
Modifications to connection strings or toolkit configuration files not tied to change tickets
HTTP requests to Splunk management port (default 8089) referencing AI Toolkit handler paths from non-administrative sessions

Detection Strategies

Correlate Splunk audit.log entries against user role assignments to flag privileged actions performed by low-privileged accounts
Baseline normal AI Toolkit REST API usage per user and alert on deviations in endpoint access patterns
Monitor for anomalous container lifecycle events initiated outside scheduled ML pipeline runs

Monitoring Recommendations

Enable verbose REST API access logging on the Splunk management port and forward logs to a centralized SIEM
Track configuration file integrity on $SPLUNK_HOME/etc/apps/Splunk_ML_Toolkit/ and related AI Toolkit paths
Review authentication events for accounts that suddenly begin accessing management endpoints they have not touched previously

How to Mitigate CVE-2026-76394

Immediate Actions Required

Upgrade Splunk AI Toolkit to version 6.0.0 or later on all affected Splunk instances
Audit existing Splunk user accounts and remove unnecessary access to environments hosting the AI Toolkit
Review Splunk audit logs for the last 90 days to identify suspicious REST API activity against AI Toolkit handlers
Rotate any credentials, tokens, or connection secrets stored in AI Toolkit configuration that may have been exposed

Patch Information

Splunk has addressed CVE-2026-76394 in Splunk AI Toolkit version 6.0.0. Administrators should upgrade the app through Splunkbase or the Splunk Cloud Platform update process. Refer to Splunk Security Advisory SVD-2026-0808 for the authoritative remediation guidance.

Workarounds

Restrict network access to the Splunk management port so only trusted administrative hosts can reach REST endpoints
Limit Splunk user account creation and enforce strong role hygiene, granting only the minimum roles required
Disable or uninstall the Splunk AI Toolkit app on instances where machine learning features are not required until patching is complete

bash

# Verify installed Splunk AI Toolkit version
$SPLUNK_HOME/bin/splunk display app Splunk_ML_Toolkit

# Restrict management port access at the host firewall (Linux example)
iptables -A INPUT -p tcp --dport 8089 -s <trusted_admin_subnet> -j ACCEPT
iptables -A INPUT -p tcp --dport 8089 -j DROP