Markdownify MCP Server allows Server-Side Request Forgery (SSRF) via the Markdownify.get() function

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 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 · score source

EPSS

• CVE-2025-5276: 0.42% estimated exploitation activity in the next 30 days; percentile 36.15 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

All versions of the package mcp-markdownify-server 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.

Published by the source

29 May 2025, 06:31 UTC

Last modified by the source

29 May 2025, 17:59 UTC

Source last checked

26 Oct 2026, 12:37 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-frq9-3hp2-xvxg

2. Revision 2 · amended · 24 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-frq9-3hp2-xvxg

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# Patch Next advisory brief: CVE-2025-5276

Advisory: Markdownify MCP Server allows Server-Side Request Forgery (SSRF) via the Markdownify.get() function
IDs: CVE-2025-5276, GHSA-frq9-3hp2-xvxg
Record: https://patchnext.com/advisories/cve-2025-5276 (revision 3, source checked 26 Oct 2026, 12:37 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm mcp-markdownify-server: affected <= 0.0.1

## Suggested inspection (read-only)
- `npm ls mcp-markdownify-server --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on mcp-markdownify-server.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-frq9-3hp2-xvxg (OSV record GHSA-frq9-3hp2-xvxg lists affected ranges: npm mcp-markdownify-server >=0 <=0.0.1)
- Verified: https://github.com/advisories/GHSA-frq9-3hp2-xvxg (GitHub-reviewed advisory GHSA-frq9-3hp2-xvxg lists affected ranges: npm mcp-markdownify-server >=0 <=0.0.1)

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