CVE-2025-5276 json
Markdownify MCP Server allows Server-Side Request Forgery (SSRF) via the Markdownify.get() function
published 2025-05-29 17 mo ago modified 2026-08-05 3 mo ago also GHSA-frq9-3hp2-xvxg , EUVD-2025-16365
- cvss
- 7.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 36%
- public exploits
- 0
- none known
Summary
Versions of the package mcp-markdownify-server before 1.0.0 are vulnerable to Server-Side Request Forgery (SSRF) via the Markdownify.get() function. An attacker can craft a prompt that, once accessed by the MCP host, can invoke the webpage-to-markdown, bing-search-to-markdown, and youtube-to-markdown tools to issue requests and read the responses to attacker-controlled URLs, potentially leaking sensitive information.
Patch / fix
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- partial
- Assessed
- 17 mo ago
Exploit prediction
0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- security.snyk.io https://security.snyk.io/vuln/SNYK-JS-MCPMARKDOWNIFYSERVER-10249387 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.2 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P |
| CNA | 3.1 | 7.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N/E:P |
| CNA | 4.0 | 6.9 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P/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 |
| CNA | 3.1 | 7.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N |
| GitHub | 3.1 | 7.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | mcp-markdownify-server | <=0.0.1 |
no fix listed |
Affected products
- n/a mcp-markdownify-server
Classification
- Weakness
-
- CWE-918 Server-Side Request Forgery
References
-
github.com
/zcaceres/markdownify-mcp/commit/0284aa8f34d32c65e20d8cda2d429b7943c9af03
web
-
security.snyk.io
/vuln/SNYK-JS-MCPMARKDOWNIFYSERVER-10249387
exploit, web
- github.com /zcaceres/markdownify-mcp/blob/224cf89f0d58616d2a5522f60f184e8391d1c9e3/src/server.ts%23L20C17-L20C29
-
nvd.nist.gov
/vuln/detail/CVE-2025-5276
advisory
-
github.com
/zcaceres/markdownify-mcp
package
-
github.com
/zcaceres/markdownify-mcp/blob/224cf89f0d58616d2a5522f60f184e8391d1c9e3/src/server.ts#L20C17-L20C29
web
Sources
- CVE List CVE-2025-5276
- GitHub Advisory GHSA-frq9-3hp2-xvxg
- NVD CVE-2025-5276
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.