CVE-2026-33438

Stirling-PDF vulnerable to DoS via add-watermark

State: Published
Severity: 6.5 Medium
Published: Mar 26, 2026
Updated: Mar 26, 2026
Reserved: Mar 19, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	6.5 Medium	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	GitHub_M

Weaknesses

CWE-770 Allocation of Resources Without Limits or Throttling

Affected Products

Product	Versions
Stirling-PDFStirling-Tools	>= 2.1.5, < 2.5.2Affected

References

https://github.com/Stirling-Tools/Stirling-PDF/security/advisories/GHSA-3932-2rfq-87xm

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.