Vulnerability · Published Apr 17, 2026 · Assigned by GitHub_M
CVE-2026-33436Stirling-PDF: Reflected XSS through crafted filename in file upload functionality
Low 3.1
In plain English
A low-severity improper input validation in Stirling-PDF from Stirling-Tools. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Stirling-Tools | Stirling-PDF | < 2.0.0 |
Weakness: CWE-20, CWE-79, CWE-116 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N