Cyber Resilience

CVE-2026-44430

SSRF in Lfprojects Mcp Registry ≤ 1.7.7

Public PoCSSRF
Published
14 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v4 6.3
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0029 21th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-44430 is a medium-severity SSRF (CWE-918) vulnerability in Lfprojects Mcp Registry. Its CVSS base score is 6.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.

The strongest mitigations our analysis identified map to AC-4 (Information Flow Enforcement) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.7, the Registry's HTTP-based namespace verification (POST /v0/auth/http, POST /v0.1/auth/http) uses safeDialContext (internal/api/handlers/v0/auth/http.go:67-110) to refuse dialling private/internal addresses when…

more

fetching the well-known public-key file from a publisher-supplied domain. The blocklist (isBlockedIP, lines 125-133) relies entirely on Go stdlib's IsLoopback / IsPrivate / IsLinkLocalUnicast / IsMulticast / IsUnspecified plus a manual CGNAT range. None of these cover IPv6 6to4 (2002::/16), NAT64 (64:ff9b::/96 and 64:ff9b:1::/48 per RFC 8215), or deprecated site-local (fec0::/10) — all of which encode arbitrary IPv4 in the address bits and tunnel to RFC1918 / cloud-metadata services on dual-stack / NAT64-enabled hosts. This vulnerability is fixed in 1.7.7.

CWE(s)

AI Security AnalysisAI

AI Category
AI Agent Protocols and Integrations
Risk Domain
Protocol-Specific Risks
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: mcp

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Incomplete SSRF blocklist (CWE-918) allows tunneling to internal/private addresses via specific IPv6 ranges.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-44428Same product: Lfprojects Mcp Registry
CVE-2026-44429Same product: Lfprojects Mcp Registry
CVE-2025-68145Same vendor: Lfprojects
CVE-2026-25536Same vendor: Lfprojects
CVE-2026-29791Same vendor: Lfprojects
CVE-2026-52870Same vendor: Lfprojects
CVE-2026-27896Same vendor: Lfprojects
CVE-2026-34237Same vendor: Lfprojects
CVE-2026-2393Same vendor: Lfprojects
CVE-2026-59950Same vendor: Lfprojects

Affected Assets

lfprojects
mcp registry
≤ 1.7.7

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • AC-4 Information Flow Enforcement
  • SI-10 Information Input Validation
  • SC-7 Boundary Protection
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.3.6
  • V1.5.3
  • V5.3.2
  • V10.4.7

Mitigating Controls (NIST 800-53 r5) AI

prevent

Enforces information flow policies that block outbound fetches to private/internal IPv4/IPv6 ranges during namespace verification, directly closing the incomplete isBlockedIP allow-list.

prevent

Requires validation of untrusted publisher-supplied domains/URLs before the HTTP dial, preventing use of 6to4, NAT64, and site-local encodings that tunnel to internal endpoints.

prevent

Boundary protection mechanisms can restrict egress to only approved external address spaces, mitigating SSRF via dual-stack or NAT64 tunnels even when application-level checks are incomplete.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly include input validation and destination allow-listing that prevent SSRF.

DE.CM-09 partial match
prevents

Runtime monitoring of web applications and services can detect anomalous outbound requests indicative of SSRF.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover and record SSRF flaws in web applications.

PR.IR-01 partial match
prevents

Network segmentation and egress controls can limit the damage from successful SSRF requests.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Operational threat data describing SSRF campaigns can be used to tighten outbound-request allow-lists and detection rules before attackers exploit them.

References