Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

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

Quick assessment

Affected
Stirling-Tools Stirling-PDF
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Stirling-PDF是Stirling Tools开源的一个使用 Docker 的强大、本地托管的基于 Web 的 PDF 操作工具。 Stirling-PDF 2.5.2之前版本存在安全漏洞，该漏洞源于水印功能对fontSize和widthSpacer参数验证不足，可能导致拒绝服务攻击。

CVSS 6.5 · Medium EPSS 0.44% · P37
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-33438

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Stirling-PDF vulnerable to DoS via add-watermark
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
不加限制或调节的资源分配
Source: CVE Program / CVE List V5
Vulnerability Title
Stirling-PDF 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Stirling-PDF是Stirling Tools开源的一个使用 Docker 的强大、本地托管的基于 Web 的 PDF 操作工具。 Stirling-PDF 2.5.2之前版本存在安全漏洞，该漏洞源于水印功能对fontSize和widthSpacer参数验证不足，可能导致拒绝服务攻击。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Stirling-Tools Stirling-PDF >= 2.1.5, < 2.5.2 -

II. Public POCs for CVE-2026-33438

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-33438

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-33438 (1)

IV. Related Vulnerabilities

Same product: Stirling-PDF
Same vendor: Stirling-Tools
Same weakness: CWE-770

V. Comments for CVE-2026-33438

No comments yet

Leave a comment