CVE-2026-44429

Published: Mag 14, 2026 Last Modified: Mag 15, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 5,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: passive
Confidentiality: N/A
Integrity: N/A
Availability: N/A
MEDIUM 5,4
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: low
User Interaction: required
Scope: changed
Confidentiality: low
Integrity: low
Availability: none

Description

AI Translation Available

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 public catalogue UI served at GET / (file internal/api/handlers/v0/ui_index.html) is vulnerable to stored cross-site scripting via the server.websiteUrl field of any published server.json. Server-side validation in internal/validators/validators.go (validateWebsiteURL) only checks that the URL parses, is absolute, and uses the https scheme; it does not reject quote characters. Client-side, the value is interpolated into a double-quoted href attribute via innerHTML, using a homegrown escapeHtml helper that performs the standard textContent → innerHTML round-trip. Per the HTML serialisation algorithm, that round-trip encodes only &, <, > and U+00A0 inside text nodes — it does not encode ' or '. A literal ' in websiteUrl therefore breaks out of the href attribute, allowing arbitrary on* event handlers to be appended to the same <a> element. The Content-Security-Policy on / is script-src 'self' 'unsafe-inline' https://cdn.tailwindcss.com, so the injected event handlers execute. Any user able to obtain a publish token (e.g. via POST /v0/auth/github-at with their own GitHub account, or POST /v0/auth/none on a deployment that has anonymous auth enabled) can plant a poisoned record visible to every visitor of the registry homepage. This vulnerability is fixed in 1.7.7.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0004
Percentile
0,1th
Updated

EPSS Score Trend (Last 6 Days)

79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Stable
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Confidentiality Integrity Availability
Potential Impacts:
Bypass Protection Mechanism Read Application Data Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies: AI/ML, Web Based, Web Server
Likelihood of Exploit: High
View CWE Details
116

Improper Encoding or Escaping of Output

Draft
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability Access Control
Potential Impacts:
Modify Application Data Execute Unauthorized Code Or Commands Bypass Protection Mechanism
Applicable Platforms
Technologies: Not Technology-Specific, AI/ML, Database Server, Web Server
Likelihood of Exploit: High
View CWE Details
Application

Mcp Registry by Lfprojects

Product Information
Vendor Lfprojects
Product Mcp Registry
Version Range Affected
To 1.7.7 (exclusive)
cpe:2.3:a:lfprojects:mcp_registry:*:*:*:*:*:*:*:*
Common Platform Enumeration - Standardized vulnerability identification
https://github.com/modelcontextprotocol/registry/security/a…
https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-rqv2-…
https://github.com/modelcontextprotocol/registry/security/a…
https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-rqv2-…