CVE-2026-111385: Nezha 2.1.0 before 2.3.15 Host Header Injection via MCP Transfer Tools
Nezha from 2.1.0 before 2.3.15 contains a host header injection vulnerability in mintTransferTool that builds fs.downloadurl and fs.uploadurl transfer URLs from the unvalidated Host header. Attackers who control the Host header seen on a victim's MCP request can redirect file uploads or capture one-time download tokens and replay them to exfiltrate files.
Affected Software
Event History
Frequently Asked Questions
Which deployments are affected?
Nezha versions from 2.1.0 up to, but not including, 2.3.15 are affected. The issue is in the MCP transfer tool functionality that constructs upload and download URLs.
What must an attacker be able to do to exploit this?
An attacker must be able to control the Host header observed on a victim's MCP request. Exploitation can redirect file uploads or allow capture and replay of one-time download tokens.
What is the potential impact of a successful attack?
A successful attacker may redirect uploaded files or replay captured one-time download tokens to exfiltrate files. The reported impact includes low confidentiality and integrity impact, with no availability impact.