CVE-2026-33438 MEDIUM

CVE-2026-33438: Stirling-PDF vulnerable to DoS via add-watermark

Vendor Stirling-Tools
Product Stirling-PDF
Weakness CWE-770 · Uncontrolled resource consumption
Published March 26, 2026
Last update March 26, 2026
View on NVD All CVEs

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

Stirling-PDF is a locally hosted web application that allows you to perform various operations on PDF files. Versions starting in 2.1.5 and prior to 2.5.2 have Denial of Service (DoS) vulnerability in the Stirling-PDF watermark functionality (`/api/v1/security/add-watermark` endpoint). The vulnerability allows authenticated users to cause resource exhaustion and server crashes by providing extreme values for the `fontSize` and `widthSpacer` parameters. Version 2.5.2 patches the issue.

Key dates

02Disclosure timeline

March 26, 2026 CVE published
March 26, 2026 Record updated