CVE-2025-55161 Stirling-PDF SSRF vulnerability on /api/v1/convert/markdown/pdf

High 8.6 Published 11 Aug 2025 Updated 12 Aug 2025

Attackers can bypass sanitization in the Markdown-to-PDF conversion endpoint to perform Server-Side Request Forgery, potentially accessing internal resources.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-55161?

CVE-2025-55161 is a high-severity server-side request forgery vulnerability in Stirling-Tools Stirling-PDF, published on 11 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

Stirling-PDF is a locally hosted web application that performs various operations on PDF files. Prior to version 1.1.0, when using the /api/v1/convert/markdown/pdf endpoint to convert Markdown to PDF, the backend calls a third-party tool to process it and includes a sanitizer for security sanitization which can be bypassed and result in SSRF. This issue has been patched in version 1.1.0.

Weakness: CWE-918

Which versions are affected by CVE-2025-55161?

It affects 1 product.

Products include Stirlingpdf Stirling Pdf.

How do I fix CVE-2025-55161?

No fix has been published for CVE-2025-55161 yet. Limit exposure of the affected software until one is available.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2025-55161 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-55161 exists.

Public exploit code: 1 Nuclei template.

Sources

Also known as GHSA-ff33-grr6-rmvp.