What’s Vulnerable › Vulnerabilities

CVE-2026-111385: Nezha 2.1.0 before 2.3.15 Host Header Injection via MCP Transfer Tools

• Severity: medium (CVSS 4.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-16 · updated 2026-10-21
• Weakness: CWE-601

Description

Nezha from 2.1.0 before 2.3.15 contains a host header injection vulnerability in mintTransferTool that builds fs.download_url and fs.upload_url 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 products

• nezhahq nezha: from 2.1.0 before 2.3.15 — fixed in 2.3.15

How to fix

Upgrade to a fixed version: nezhahq nezha 2.3.15. Check the vendor advisory for mitigations.

References

• https://github.com/nezhahq/nezha/commit/36b742a7e9a81ed782363dd19efd77b7030fbd0f
• https://github.com/nezhahq/nezha/commit/c726930833937a0aebb2a924064f236faea889f6
• https://github.com/nezhahq/nezha/security/advisories/GHSA-rj3w-jrj7-x7c3
• https://www.vulncheck.com/advisories/nezha-2.1.0-before-2.3.15-host-header-injection-via-mcp-transfer-tools
• https://github.com/nezhahq/nezha/security/advisories/GHSA-rj3w-jrj7-x7c3

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