{
  "threat_severity" : "Important",
  "public_date" : "2026-04-02T14:52:39Z",
  "bugzilla" : {
    "description" : "fastmcp: FastMCP: Authenticated Server-Side Request Forgery via path traversal in OpenAPI path parameters",
    "id" : "2454434",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2454434"
  },
  "cvss3" : {
    "cvss3_base_score" : "8.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-918",
  "details" : [ "FastMCP is a Pythonic way to build MCP servers and clients. Prior to version 3.2.0, the OpenAPIProvider in FastMCP exposes internal APIs to MCP clients by parsing OpenAPI specifications. The RequestDirector class is responsible for constructing HTTP requests to the backend service. A vulnerability exists in the _build_url() method. When an OpenAPI operation defines path parameters (e.g., /api/v1/users/{user_id}), the system directly substitutes parameter values into the URL template string without URL-encoding. Subsequently, urllib.parse.urljoin() resolves the final URL. Since urljoin() interprets ../ sequences as directory traversal, an attacker controlling a path parameter can perform path traversal attacks to escape the intended API prefix and access arbitrary backend endpoints. This results in authenticated SSRF, as requests are sent with the authorization headers configured in the MCP provider. This issue has been patched in version 3.2.0.", "A flaw was found in FastMCP. An authenticated attacker can exploit a path traversal vulnerability in the _build_url() method of the RequestDirector class. By manipulating path parameters in an OpenAPI operation, an attacker can use directory traversal sequences (../) to bypass the intended API prefix. This allows the attacker to access arbitrary backend endpoints, leading to authenticated Server-Side Request Forgery (SSRF). Server-Side Request Forgery (SSRF) enables an attacker to compel the server-side application to send HTTP requests to an arbitrary domain." ],
  "statement" : "This is an Important severity flaw affecting FastMCP, which is utilized in Red Hat OpenShift AI, Red Hat Satellite, Hosted OpenShift Clusters, and Ansible Services. An authenticated attacker can exploit a path traversal vulnerability in FastMCP's OpenAPI path parameter handling to achieve Server-Side Request Forgery (SSRF), allowing access to arbitrary backend endpoints. As a result of a successful exploitation of this vulnerability the attacker  may be able to access private endpoints, exfiltrate data, achieving privilege escalation or by-pass security controls within the affected component.",
  "affected_release" : [ {
    "product_name" : "Red Hat Satellite 6.18",
    "release_date" : "2026-07-07T00:00:00Z",
    "advisory" : "RHSA-2026:36350",
    "cpe" : "cpe:/a:redhat:satellite:6.18::el9",
    "package" : "satellite/foreman-mcp-server-rhel9:1782739344"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-mlflow-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-datascience-cpu-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-minimal-cpu-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-pytorch-llmcompressor-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-pytorch-rocm-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-tensorflow-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-pipeline-runtime-tensorflow-rocm-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-codeserver-datascience-cpu-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-datascience-cpu-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-minimal-cpu-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-minimal-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-minimal-rocm-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-pytorch-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-pytorch-rocm-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-tensorflow-rocm-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  }, {
    "product_name" : "Red Hat OpenShift AI (RHOAI)",
    "fix_state" : "Not affected",
    "package_name" : "rhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9",
    "cpe" : "cpe:/a:redhat:openshift_ai"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-32871\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-32871\nhttps://github.com/PrefectHQ/fastmcp/commit/40bdfb6b1de0ce30609ee9ba5bb95ecd04a9fb71\nhttps://github.com/PrefectHQ/fastmcp/pull/3507\nhttps://github.com/PrefectHQ/fastmcp/releases/tag/v3.2.0\nhttps://github.com/PrefectHQ/fastmcp/security/advisories/GHSA-vv7q-7jx5-f767" ],
  "name" : "CVE-2026-32871",
  "mitigation" : {
    "value" : "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.",
    "lang" : "en:us"
  },
  "csaw" : false
}