CVE-2025-5276
Fix: zcaceres/markdownify-mcp@0284aa8CVE-2025-5276 is a Server-Side Request Forgery (SSRF) vulnerability in mcp-markdownify-server. O3 Security confirms whether CVE-2025-5276 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Markdownify MCP Server allows Server-Side Request Forgery (SSRF) via the Markdownify.get() function
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
mcp-markdownify-servernpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | mcp-markdownify-server | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mcp-markdownify-server. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of mcp-markdownify-server has shipped for CVE-2025-5276 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-5276 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-5276. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-5276 in your dependencies?
O3 detects CVE-2025-5276 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.