CVSS 4.0
Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)
Атакува се
Време до експлоатация
Атакува се по мрежата, без особени условия, без вход и без действие от потребителя.
- Експлоатация: има публичен пример за експлоатация
- Атаката може да се автоматизира
Описание
Оригинално описание
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.
Засегнати продукти
- PrefectHQ fastmcp: < 3.2.0
- Red Hat Red Hat Satellite 6.18: от 1782739344 нататък
- Red Hat Red Hat OpenShift AI (RHOAI)
Вид слабост
История
- 2 април 2026 Публикувано
Други уязвимости в PrefectHQ fastmcp
Първоизточници
- https://www.cve.org/CVERecord?id=CVE-2026-32871
- https://nvd.nist.gov/vuln/detail/CVE-2026-32871
- https://github.com/PrefectHQ/fastmcp/security/advisories/GHSA-vv7q-7jx5-f767
- https://github.com/PrefectHQ/fastmcp/pull/3507
- https://github.com/PrefectHQ/fastmcp/commit/40bdfb6b1de0ce30609ee9ba5bb95ecd04a9fb71
- https://github.com/PrefectHQ/fastmcp/releases/tag/v3.2.0
- https://access.redhat.com/security/cve/CVE-2026-32871
- https://bugzilla.redhat.com/show_bug.cgi?id=2454434
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32871.json
- https://access.redhat.com/errata/RHSA-2026:36350