Documents may contain personal, financial, legal, educational, medical or business information. Treat every uploaded file and its contents as confidential and untrusted.

The inspected API currently:

• Enables CORS without an origin allowlist.
• Accepts JSON and URL-encoded bodies up to 50 MB.
• Configures markdown-it with raw HTML enabled.
• Passes generated HTML to Puppeteer.
• Launches Puppeteer with Chromium sandbox flags disabled.

These choices require hardening before public production use. This document records code-level observations, not a penetration-test result.

• Validate file signatures and actual content, not only extensions or client MIME types.
• Enforce file size, page count, archive expansion, image dimensions and processing limits.
• Reject malformed, encrypted or unsupported files with safe errors.
• Defend against archive bombs and parser vulnerabilities.
• Keep parsers and conversion libraries updated.

• Sanitize user-provided and converted HTML with a maintained allowlist sanitizer.
• Disable arbitrary remote resource loading.
• Prevent access to local files, internal services, cloud metadata endpoints and loopback addresses.
• Avoid interpolating untrusted strings into CSS, HTML, URLs or Puppeteer configuration.
• Run Chromium in a properly isolated environment; do not rely on disabling sandbox protections as a production default.

• Restrict CORS to trusted origins.
• Add rate limits, concurrency limits and request timeouts.
• Validate all numeric and color configuration values.
• Avoid returning internal exception details to clients.
• Add authentication/authorization if private job history or persistent files are introduced.

• Use private temporary storage and unpredictable identifiers.
• Clean up files on success, failure, cancellation and expiration.
• Define retention periods and deletion behavior.
• Do not log document bodies, extracted text, secrets or sensitive filenames.
• Encrypt data in transit and protect stored files if persistence is introduced.
• Do not transmit documents to third-party conversion or AI services without clear disclosure and consent.

• Run workers with least privilege and restricted network/filesystem access.
• Monitor resource use and conversion failures without collecting document content.
• Maintain dependency and container update processes.
• Back up only data that the product intentionally retains.

If a security issue is discovered, stop the affected processing path, preserve relevant operational evidence without copying sensitive document contents, assess exposure, rotate affected credentials and notify impacted users as required.

Report vulnerabilities privately to the repository maintainers. Do not publish exploit details before maintainers have had a reasonable opportunity to investigate and release a fix.