CVE-2026-33438
Medium
Description
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.
SeverityMedium
CVSS6.5
Exploit probability—
ProductStirling Pdf
PublishedMar 26, 2026
First seenMar 26, 2026
Weakness typeCWE-770Allocation of resources without limits
How to fix
Update
- stirling stirling_pdf2.5.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| stirling stirling_pdf | 2.1.5 ≤ v < 2.5.2 | 2.5.2 |
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