# CVE-2025-59155: HackMD MCP Server Server-Side Request Forgery

Source: https://junglewise.ai/threats/cve-2025-59155-hackmd-mcp-server-server-side-request-forgery  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-09-15. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2025-59155 · Severity: medium · CVSS 4 · Published 2025-09-15

HackMD MCP Server is a backend component that handles API requests for HackMD document management. An SSRF vulnerability in HTTP mode allows attackers to redirect API calls to internal network services, potentially accessing sensitive endpoints or bypassing firewall controls without authentication.

Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2025-59155 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-59155 being exploited in the wild.

**How severe is CVE-2025-59155?** Medium severity, with a CVSS score of 4, published 15 September 2025.

**Which products and versions are affected?** hackmd-mcp (npm) SEMVER:introduced=1.4.0,fixed=1.5.0.

**Is there a fix for CVE-2025-59155?** Yes. hackmd-mcp (npm): upgrade to 1.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-59155 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2025-59155?** Check whether you run hackmd-mcp (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- hackmd-mcp (npm): upgrade to 1.5.0 or later

  ```sh
  npm install hackmd-mcp@1.5.0
  ```


## Technical details

The vulnerability is a Server-Side Request Forgery (CWE-918) affecting HackMD MCP versions 1.4.0 through 1.4.x. Attackers can inject arbitrary hackmdApiUrl values via HTTP headers (Hackmd-Api-Url) or base64-encoded JSON query parameters to force the server to make requests to attacker-controlled or internal network endpoints. The attack requires network access to the HTTP interface and no authentication. Exploitation allows reconnaissance of internal services, access to sensitive endpoints, and bypass of network access controls. The vulnerability has been patched in version 1.5.0; users should upgrade and configure ALLOWED_HACKMD_API_URLS environment variable to restrict endpoints.

## Affected products

- HackMD MCP Server 1.4.0 to 1.4.x (fixed in 1.5.0)

## Identifiers

- CVE-2025-59155
- GHSA-g5cg-6c7v-mmpw

## Timeline

- 2025-09-15: disclosed
- 2025-09-15: patched: Version 1.5.0 released

## References

- [https://github.com/yuna0x0/hackmd-mcp/security/advisories/GHSA-g5cg-6c7v-mmpw](https://github.com/yuna0x0/hackmd-mcp/security/advisories/GHSA-g5cg-6c7v-mmpw)