CVE-2026-59973Public exploitNetwork attack vectorHinoki check available

Authenticated SSRF via incomplete external reference validation

Published Sep 15, 2026 · Updated Sep 15, 2026

SSRF in AgentFront FrontMCP and its OpenAPI packages allows remote authenticated users to reach internal services through crafted specs. The loadOpenAPISpec path passes untrusted URLs and external references to a guard that neither resolves and pins addresses nor revalidates redirects or normalizes IPv4-mapped IPv6. Exploitation requires permission to import or configure a specification in a hosted or multi-user deployment and exposes private endpoints to backend-origin requests.

CVSS severity8.5
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

SSRF in AgentFront FrontMCP and its OpenAPI packages allows remote authenticated users to reach internal services through crafted specs. The loadOpenAPISpec path passes untrusted URLs and external references to a guard that neither resolves and pins addresses nor revalidates redirects or normalizes IPv4-mapped IPv6. Exploitation requires permission to import or configure a specification in a hosted or multi-user deployment and exposes private endpoints to backend-origin requests.

The record

CVE
CVE-2026-59973
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
AgentFront
Product
@frontmcp/adapters
Classifications
CWE-918, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

AgentFront · @frontmcp/adaptersversion=< 1.5.0
AgentFront · FrontMCPversion=< 1.5.0
AgentFront · mcp-from-openapiversion=< 2.5.0

Published CVSS scores

8.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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