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Findings

Vulnerability · CVE-2025-55161

stirlingpdf stirling_pdf Server-Side Request Forgery (SSRF)

Published Oct 7, 2025 · corrected/updated Oct 7, 2025 · stirlingpdf stirling_pdf · evidence confidence very high

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.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2025-55161 is a unknown public vulnerability record for stirlingpdf stirling_pdf. CISA lists it as known exploited. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether stirlingpdf stirling_pdf is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: stirlingpdf stirling_pdf. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: no CVSS/EPSS yet. CISA lists it as known exploited. Sources contributing to this record: cve_org, vulncheck_kev. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Confirmed in CISA KEV since Oct 7, 2025. Listed in CISA KEV and VulnCheck KEV.

  • Patch and remediation

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Oct 7, 2025 · VulnCheck KEV

    Detected

    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.

  2. Oct 7, 2025 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected

  • vendor stirlingpdf stirling_pdfversion unspecified

Sources

  • CVE.orgVulnerability recordCVE-2025-55161

    Official CVE identifier

    cve.org
  • VulnCheck KEVConfirmed exploitationCVE-2025-55161

    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

    vulncheck.com

References