CVE-2026-33438

Name: CVE-2026-33438
Creator: NVD / NIST
Published: 2026-03-26T17:16:40.657+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.40%

Last modified Jun 17, 2026

CVE-2026-33438 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. 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). EPSS estimates a 0.40% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.40%

31.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-770

Affected Software

Vendor	Product	Versions
Stirling	Stirling Pdf	>= 2.1.5, < 2.5.2

References

https://github.com/Stirling-Tools/Stirling-PDF/security/advisories/GHSA-3932-2rfq-87xmExploit, Vendor Advisory
https://github.com/Stirling-Tools/Stirling-PDF/security/advisories/GHSA-3932-2rfq-87xmExploit, Vendor Advisory

Timeline

Published: Mar 26, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-33438?

How severe is CVE-2026-33438?

CVE-2026-33438 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2026-33438?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-33438?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST