Token theft via custom API endpoint forwarding
Published Oct 7, 2026 · Updated Oct 7, 2026
Splunk MCP Server before 1.2.1 allows remote authenticated users to capture another user's Splunk token through a custom API tool. When a user executes an API-type custom tool, the server sends that user's Splunk platform authentication token to its configured endpoint, even when another user controls the URL. Exploitation requires a user with the mcp_tool_execute capability to run another user's custom tool; the captured token permits access and actions as the executing user.
Summary
What happened
Splunk MCP Server before 1.2.1 allows remote authenticated users to capture another user's Splunk token through a custom API tool. When a user executes an API-type custom tool, the server sends that user's Splunk platform authentication token to its configured endpoint, even when another user controls the URL. Exploitation requires a user with the mcp_tool_execute capability to run another user's custom tool; the captured token permits access and actions as the executing user.
The record
- CVE
- CVE-2026-76286
- Published
- Oct 7, 2026
- Updated
- Oct 7, 2026
- Vendor
- Splunk, Inc.
- Product
- Splunk MCP Server
- Classifications
- T1528
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 7, 2026CVE publishedPublication date reported by the CVE source.
- Oct 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=1.2 <1.2.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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