CVE-2026-39885
Last modified
CVE-2026-39885 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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. EPSS estimates a 0.32% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Agentfront | \@Frontmcp\/Adapters | < 1.0.4 |
| Agentfront | \@Frontmcp\/Sdk | < 1.0.4 |
| Agentfront | Frontmcp | < 1.0.4 |
| Frontmcp | Mcp-From-Openapi | < 2.3.0 |
References
- https://github.com/agentfront/frontmcp/security/advisories/GHSA-v6ph-xcq9-qxxjExploit, Vendor Advisory
- https://github.com/agentfront/frontmcp/security/advisories/GHSA-v6ph-xcq9-qxxjExploit, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-39885?
How severe is CVE-2026-39885?
How do I fix CVE-2026-39885?
Are you affected by CVE-2026-39885?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST