CVE-2025-59155 Details
Description
hackmd-mcp is a Model Context Protocol server for integrating HackMD's note-taking platform with AI assistants. From 1.4.0 to before 1.5.0, hackmd-mcp contains a server-side request forgery (SSRF) vulnerability when the server is run in HTTP transport mode. Arbitrary hackmdApiUrl values supplied via the Hackmd-Api-Url HTTP header or a base64-encoded JSON query parameter are accepted without validation, allowing attackers to redirect outbound API requests to internal network services, access internal endpoints, perform network reconnaissance, and bypass network access controls. The stdio transport mode is not affected because it only accepts stdio requests. The issue is fixed in version 1.5.0, which enforces allowed endpoints and supports the ALLOWED_HACKMD_API_URLS environment variable. Users should update to 1.5.0 or later or apply documented mitigations such as switching to stdio mode, restricting outbound network access, or filtering the Hackmd-Api-Url header and related query parameter via a reverse proxy.
A server-side request forgery (SSRF) vulnerability has been identified in HackMD MCP versions 1.4.0 prior to 1.5.0. This vulnerability occurs when the server is run in HTTP transport mode, allowing attackers to send arbitrary hackmdApiUrl values via the Hackmd-Api-Url HTTP header or a base64-encoded JSON query parameter. The lack of validation on these inputs enables redirection of outbound API requests to internal network services, potentially accessing sensitive internal endpoints, performing network reconnaissance, and bypassing network access controls. The stdio transport mode is not affected as it only accepts stdio requests.
Users can update to version 1.5.0 or later, which includes a default allowlist for HackMD API URLs. Alternatively, the HTTP transport mode can be disabled by using stdio mode, or network access can be restricted through firewall rules or reverse proxy filtering.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 15, 2025CISA-ADP
Assessed Sep 15, 2025References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/yuna0x0/hackmd-mcp/commit/43936c78a5bb3dedc74e8f080607a1125caa8c13 | [email protected] | Source CodeVendor |
| https://github.com/yuna0x0/hackmd-mcp/security/advisories/GHSA-g5cg-6c7v-mmpw | [email protected] | AdvisoryRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-918 | Server-Side Request Forgery (SSRF) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| yuna0x0 hackmd-mcp | All versions |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Sep 15, 2025 | New CVE Received | [email protected] |