CVE intelligence and bounded remediation
CVE-2026-33436 — Stirling-PDF is a locally hosted web application that facilitates various operations on PDF files
Stirling-PDF is a locally hosted web application that facilitates various operations on PDF files. In versions prior to 2.0.0, file upload endpoints render user-supplied filenames directly into HTML using unsafe methods like innerHTML without sanitization. An attacker can craft a file with a malicious filename containing JavaScript that executes in the uploading user's browser context, resulting in reflected XSS. The issue affects numerous upload endpoints across the application. The issue has been fixed in version 2.0.0.
- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Published
- 2026-04-17
- CISA KEV
- Not currently listed
- Ecosystem
- javascript/npm
- Weaknesses
- CWE-20, CWE-79, CWE-116
Affected products
- stirlingpdf / stirling_pdf
Matched remediation archetype
Cross-site scripting and unsafe browser output
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
- Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
- Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.
Remediate safely
- Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
- Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
- Update affected rendering components and add tests for every output context using inert sentinel markup.
Authoritative sources
Complete CVE record and remediation plan
The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.