CVE-2026-20205 | Sensitive Information Disclosure in ''_internal'' index in Splunk MCP Server app

In Splunk MCP Server app versions below 1.0.3 , a user who holds a role with access to the Splunk `_internal` index or possesses the high-privilege capability `mcp_tool_admin` could view users session and authorization tokens in clear text.<br><br>The vulnerability would require either local access to the log files or administrative access to internal indexes, which by default only the admin role receives. <br><br>Review roles and capabilities on your instance and restrict internal index access to administrator-level roles. See [Define roles on the Splunk platform with capabilities](https://docs.splunk.com/Documentation/Splunk/latest/Security/Rolesandcapabilities) and [Connecting to MCP Server and Admin settings](https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/connecting-to-mcp-server-and-admin-settings) in the Splunk documentation for more information.

Published: 2026-04-15 Last update: 2026-04-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-20205 is rated Low Risk (34.4/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-20205

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-21 0.04% 0.05% +0.01%
2 2026-04-16 0.04%

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20205

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.2 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.2 5.9 [email protected]

Weakness enumeration for CVE-2026-20205

Affected software / configurations for CVE-2026-20205

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-20205

cvelogic Threat Intelligence