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

Is it exploited?

Reported, not confirmed by CISA. VulnCheck KEV lists it as exploited in the wild. CISA has not added it to its Known Exploited Vulnerabilities catalog as of 29 Oct 2026.

VulnCheck KEV lists it since 7 Oct 2025. It cites 96 public reports, the first from 7 Oct 2025.

• dashboard.shadowserver.org
• dashboard.shadowserver.org
• dashboard.shadowserver.org

How likely is exploitation in the next 30 days?

2.1%

Up from 2% on 23 Oct 2026.

EPSS score, percentile 81.4 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

8.6 High

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• < 1.1.0

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; VulnCheck KEV, as of 30 Oct 2026; FIRST EPSS, as of 30 Oct 2026; CVE List, as of 30 Oct 2026. About the data.

Description

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

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.

Source: CVE List, as of 30 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 30 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

Source: CVE List, as of 30 Oct 2026. About the data.

Timeline