CVE-2026-33436 LOW

CVE-2026-33436: Stirling-PDF: Reflected XSS through crafted filename in file upload functionality

Vendor Stirling-Tools
Product Stirling-PDF
Weakness CWE-20 · Input validation
Published April 17, 2026
Last update April 20, 2026

CVSS base score

3.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 17, 2026 CVE published
April 20, 2026 Record updated