CVE-2026-39885: FrontMCP is a TypeScript-first framework for the Model Context Protocol (MCP)

This week

HIGH 7.5REMOTEUPGRADEUPGRADEUPGRADE

CVE-2026-39885 is a high-severity flaw (CVSS 7.5) affecting \@frontmcp\/adapters, \@frontmcp\/sdk, frontmcp. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 fetc

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 66%)
CISA exploited list	No
Weakness	CWE-918
Published	2026-04-08
Last modified	2026-07-24

Publisher (CNA): GitHub, Inc. · Vendor: agentfront · frontmcp

Last updated 2026-07-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-08 21:17 UTCPublished CVE record published
2026-07-24 21:10 UTCUpdated Record last modified

agentfront \@frontmcp\/adapters UPGRADE

Affected: < 1.0.4

Fixed in: 1.0.4

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls frontmcpadapters

2. UPGRADE to 1.0.4

npm install frontmcpadapters@">=1.0.4"

agentfront \@frontmcp\/sdk UPGRADE

Affected: < 1.0.4

Fixed in: 1.0.4

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls frontmcpsdk

2. UPGRADE to 1.0.4

npm install frontmcpsdk@">=1.0.4"

agentfront frontmcp UPGRADE

Affected: < 1.0.4

Fixed in: 1.0.4

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls frontmcp

2. UPGRADE to 1.0.4

npm install frontmcp@">=1.0.4"

frontmcp mcp-from-openapi UPGRADE

Affected: < 2.3.0

Fixed in: 2.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls mcp-from-openapi

2. UPGRADE to 2.3.0

npm install mcp-from-openapi@">=2.3.0"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-39885?

\@frontmcp\/adapters: upgrade to 1.0.4; \@frontmcp\/sdk: upgrade to 1.0.4; frontmcp: upgrade to 1.0.4. Exact commands for each OS are on this page.

Is CVE-2026-39885 being exploited?

CVE-2026-39885 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-39885 affect?

CVE-2026-39885 affects \@frontmcp\/adapters, \@frontmcp\/sdk, frontmcp. Severity is high (CVSS 7.5). 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

How urgent is CVE-2026-39885?

Priority 45/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

References

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