CVE-2026-20137: Splunk Enterprise Auth Bypass Vulnerability

CVE-2026-20137 Overview

CVE-2026-20137 is an Authorization Bypass vulnerability affecting Splunk Enterprise and Splunk Cloud Platform. The vulnerability allows a low-privileged user who does not hold the "admin" or "power" Splunk roles to bypass SPL (Splunk Processing Language) safeguards for risky commands. Exploitation is achieved by creating a Data Model containing an injected SPL query within an object, leveraging a path traversal vulnerability to circumvent security controls.

Critical Impact

Low-privileged attackers can bypass SPL safeguards to execute risky commands, potentially leading to unauthorized information disclosure within the Splunk environment.

Affected Products

• Splunk Enterprise versions below 10.2.0, 10.0.3, 9.4.5, 9.3.7, and 9.2.9
• Splunk Cloud Platform versions below 10.1.2507.0, 10.0.2503.9, 9.3.2411.112, and 9.3.2408.122

Discovery Timeline

• 2026-02-18 - CVE-2026-20137 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2026-20137

Vulnerability Analysis

This vulnerability combines two security weaknesses: an authorization bypass and a path traversal flaw. Splunk Enterprise implements SPL safeguards to restrict low-privileged users from executing dangerous or risky commands. However, the Data Model creation functionality does not properly validate SPL queries embedded within objects, allowing attackers to inject malicious SPL commands.

The path traversal component enables attackers to reference resources outside the intended scope, effectively bypassing the safeguards that would normally block risky command execution. This represents a failure in the defense-in-depth strategy that Splunk employs to protect sensitive operations from unauthorized users.

The vulnerability is classified under CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), indicating that successful exploitation could lead to unauthorized access to confidential data within the Splunk environment.

Root Cause

The root cause stems from insufficient input validation in the Data Model creation workflow. When users create Data Models with embedded SPL queries, the application fails to properly sanitize path components and validate that the SPL content adheres to the user's privilege level. The path traversal vulnerability allows attackers to reference objects and execute queries that should be restricted based on their role permissions.

Attack Vector

The attack requires network access and a valid low-privileged Splunk account. An attacker must craft a malicious Data Model containing:

1. A specially constructed object with an injected SPL query
2. Path traversal sequences that bypass the safeguard checks

The attack requires user interaction (such as another user viewing the malicious Data Model) to fully exploit, which limits the attack surface. The vulnerability affects confidentiality by potentially exposing information the attacker should not have access to.

The attack flow involves creating a Data Model through the Splunk web interface or API, embedding a crafted SPL query within an object definition that includes path traversal elements to bypass the risky command safeguards.

Detection Methods for CVE-2026-20137

Indicators of Compromise

• Unusual Data Model creation activity from low-privileged user accounts
• Data Models containing path traversal patterns such as ../ or encoded variants
• SPL queries in Data Models that reference risky commands from non-admin users
• Audit logs showing unauthorized access attempts to restricted data or indexes

Detection Strategies

• Monitor Splunk audit logs for Data Model creation and modification events from users without admin or power roles
• Implement alerts for SPL queries containing path traversal patterns or risky command keywords
• Review Data Model configurations for suspicious or unexpected object definitions
• Deploy SentinelOne Singularity Platform to detect and correlate suspicious activity patterns across your Splunk infrastructure

Monitoring Recommendations

• Enable verbose auditing for Data Model operations in Splunk
• Configure real-time alerts for risky SPL command execution attempts
• Regularly review user roles and permissions to ensure principle of least privilege
• Implement centralized log aggregation to correlate Splunk activity with other security events

How to Mitigate CVE-2026-20137

Immediate Actions Required

• Upgrade Splunk Enterprise to version 10.2.0, 10.0.3, 9.4.5, 9.3.7, or 9.2.9 or later depending on your version branch
• Upgrade Splunk Cloud Platform to version 10.1.2507.0, 10.0.2503.9, 9.3.2411.112, or 9.3.2408.122 or later
• Review and audit existing Data Models for suspicious SPL content
• Restrict Data Model creation permissions to trusted users until patches are applied

Patch Information

Splunk has released security updates to address this vulnerability. Refer to the Splunk Security Advisory SVD-2026-0202 for detailed patch information and upgrade instructions specific to your deployment.

For Splunk Cloud Platform customers, updates are typically applied automatically by Splunk. Contact Splunk support to verify your instance has been patched.

Workarounds

• Temporarily disable Data Model creation for non-admin and non-power users until patches can be applied
• Implement additional access controls on sensitive indexes and data sources
• Enable enhanced auditing to detect potential exploitation attempts
• Consider network segmentation to limit access to Splunk management interfaces
• Review and remove unnecessary user accounts that may pose exploitation risks

# Example: Review Data Model permissions in Splunk
# Check current Data Model access controls
splunk list datamodel-permissions -auth admin:password

# Restrict Data Model creation to admin role only (temporary workaround)
# Edit authorize.conf to limit capabilities
# Note: Apply through Splunk configuration management