Review reviewHigh

CVE-2026-39885

agentfront frontmcp, adapters, sdk

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 untrust...

CVSS: 7.5
EPSS: 0.32%
CISA KEV: Not listed
Published: 2026.04.09

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.32%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: agentfront frontmcp, adapters, sdk
Affected versions: >= < 1.0.4, >= < 2.3.0, < 1.0.4, < 2.3.0
Fixed versions: 1.0.4, 2.3.0

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that agentfront frontmcp, adapters, sdk and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CWE: CWE-918