SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-33438

Stirling-PDF is a locally hosted web application that allows you to perform various operations on PDF files.

MEDIUM 6.5EPSS 0.40%

Does this matter?

Lower severity and a low EPSS score (0.40%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS
0.40% probability · 33th percentile
CISA KEV
Not listed
Weakness
CWE-770
Affected
stirling/stirling pdf
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.