Server-Side Request Forgery (SSRF) through Custom API Tools in Splunk MCP Server

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-76286",
    "assignerOrgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
    "assignerShortName": "cisco",
    "dateUpdated": "2026-10-08T18:00:27.987Z",
    "dateReserved": "2026-08-19T12:02:03.622Z",
    "datePublished": "2026-10-07T20:46:40.297Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "d1c1063e-7a18-46af-9102-31f8928bc633",
        "shortName": "cisco",
        "dateUpdated": "2026-10-07T20:46:40.297Z"
      },
      "datePublic": "2026-10-07T00:00:00.000Z",
      "title": "Server-Side Request Forgery (SSRF) through Custom API Tools in Splunk MCP Server",
      "descriptions": [
        {
          "lang": "en",
          "value": "In Splunk MCP Server versions below 1.2.1, Splunk MCP Server could send the Splunk platform authentication token of a user who runs a custom Application Programming Interface (API) tool to the URL configured for that tool. If another user controls that URL, they could capture the token and use it to access data and perform actions as the user who ran the tool. Successful exploitation requires a user who holds a role that contains the mcp_tool_execute capability to run a custom API tool configured by another user. For more information see Configure the Splunk MCP Server (https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/1.2/configure-the-splunk-mcp-server) and Managing custom tools in Splunk MCP Server (https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/1.2/managing-custom-tools-in-splunk-mcp-server) in the Splunk documentation.",
          "supportingMedia": [
            {
              "type": "text/markdown",
              "base64": false,
              "value": "In Splunk MCP Server versions below 1.2.1, Splunk MCP Server could send the Splunk platform authentication token of a user who runs a custom Application Programming Interface (API) tool to the URL configured for that tool. If another user controls that URL, they could capture the token and use it to access data and perform actions as the user who ran the tool. Successful exploitation requires a user who holds a role that contains the mcp_tool_execute capability to run a custom API tool configured by another user. For more information see [Configure the Splunk MCP Server](https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/1.2/configure-the-splunk-mcp-server) and [Managing custom tools in Splunk MCP Server](https://help.splunk.com/en/splunk-enterprise/mcp-server-for-splunk-platform/1.2/managing-custom-tools-in-splunk-mcp-server) in the Splunk documentation."
            }
          ]
        }
      ],
      "affected": [
        {
          "vendor": "Splunk",
          "product": "Splunk MCP Server",
          "modules": [
            "REST API"
          ],
          "versions": [
            {
              "version": "1.2",
              "status": "affected",
              "versionType": "custom",
              "lessThan": "1.2.1"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.",
              "cweId": "CWE-918",
              "type": "cwe"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://advisory.splunk.com/advisories/SVD-2026-1004"
        }
      ],
      "metrics": [
        {
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ],
          "cvssV3_1": {
            "version": "3.1",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:L/A:L",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM"
          }
        }
      ],
      "workarounds": [
        {
          "lang": "en",
          "value": "Turn off or remove the Splunk MCP Server app. For more information see [Manage app and add-on objects](https://help.splunk.com/en/splunk-enterprise/administer/admin-manual/10.2/meet-splunk-apps/manage-app-and-add-on-objects) in the Splunk documentation."
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade Splunk MCP Server to version 1.2.1 or higher."
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Kuniyoshi Noguchi (KuniNogu)",
          "type": "reporter"
        }
      ]
    },
    "adp": [
      {
        "providerMetadata": {
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP",
          "dateUpdated": "2026-10-08T18:00:27.987Z"
        },
        "title": "CISA ADP Vulnrichment",
        "metrics": [
          {}
        ]
      }
    ]
  }
}