CVE-2025-59155 json
hackmd-mcp server-side request forgery in HTTP transport mode
published 2025-09-15 13 mo ago modified 2026-06-17 4 mo ago also GHSA-g5cg-6c7v-mmpw , EUVD-2025-29214
- cvss
- 6.9
- version 4.0, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 29%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- npm hackmd-mcp 1.5.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 13 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N |
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | hackmd-mcp | >=1.4.0, <1.5.0 |
1.5.0 |
Affected products
- yuna0x0 hackmd-mcp
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
-
github.com
/yuna0x0/hackmd-mcp/commit/43936c78a5bb3dedc74e8f080607a1125caa8c13
web
-
github.com
/yuna0x0/hackmd-mcp/security/advisories/GHSA-g5cg-6c7v-mmpw
web
-
nvd.nist.gov
/vuln/detail/CVE-2025-59155
advisory
-
github.com
/yuna0x0/hackmd-mcp
package
-
github.com
/yuna0x0/hackmd-mcp/releases/tag/v1.5.0
web
Sources
- CVE List CVE-2025-59155
- GitHub Advisory GHSA-g5cg-6c7v-mmpw
- NVD CVE-2025-59155
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