CVE-2026-39885

Severity CVSS v4.0:

Pending analysis

Type:

CWE-918 Server-Side Request Forgery (SSRF)

Publication date:

08/04/2026

Last modified:

15/04/2026

Description

FrontMCP is a TypeScript-first framework for the Model Context Protocol (MCP). Prior to 2.3.0, the mcp-from-openapi library uses @apidevtools/json-schema-ref-parser to dereference $ref pointers in OpenAPI specifications without configuring any URL restrictions or custom resolvers. A malicious OpenAPI specification containing $ref values pointing to internal network addresses, cloud metadata endpoints, or local files will cause the library to fetch those resources during the initialize() call. This enables Server-Side Request Forgery (SSRF) and local file read attacks when processing untrusted OpenAPI specifications. This vulnerability is fixed in 2.3.0.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N CVSS v3.1 Severity and Metrics:

Base Score: 7.50 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): High
Integrity (I): None
Availability (A): None

Base Score 3.x

7.50

Severity 3.x

HIGH

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:agentfront:\@frontmcp\/adapters::::::node.js::*		1.0.4 (excluding)
cpe:2.3:a:agentfront:\@frontmcp\/sdk::::::node.js::*		1.0.4 (excluding)
cpe:2.3:a:agentfront:frontmcp::::::node.js::*		1.0.4 (excluding)
cpe:2.3:a:frontmcp:mcp-from-openapi::::::node.js::*		2.3.0 (excluding)

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-39885

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools