VDB-353665 · CVE-2026-33438 · GHSA-3932-2rfq-87xm

Stirling-Tools Stirling-PDF up to 2.5.1 PDF File Parser add-watermark widthSpacer allocation of resources

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.3	$0-$5k	0.00

Summaryinfo

A vulnerability marked as problematic has been reported in Stirling-Tools Stirling-PDF up to 2.5.1. This issue affects some unknown processing of the file /api/v1/security/add-watermark of the component PDF File Parser. This manipulation of the argument widthSpacer causes allocation of resources. This vulnerability is registered as CVE-2026-33438. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Stirling-Tools Stirling-PDF up to 2.5.1. Affected by this vulnerability is an unknown code of the file /api/v1/security/add-watermark of the component PDF File Parser. The manipulation of the argument widthSpacer with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. As an impact it is known to affect availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-33438 since 03/19/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 2.5.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-16262). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

Stirling-Tools

Name

Stirling-PDF

Version

Website

Product: https://github.com/Stirling-Tools/Stirling-PDF/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 4.3
VulDB Temp Score: 4.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 6.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Stirling-PDF 2.5.2

Timelineinfo

03/19/2026 CVE reserved
03/26/2026 +7 days Advisory disclosed
03/26/2026 +0 days VulDB entry created
03/26/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-3932-2rfq-87xm
Status: Confirmed

CVE: CVE-2026-33438 (🔒)
GCVE (CVE): GCVE-0-2026-33438
GCVE (VulDB): GCVE-100-353665
EUVD: 🔒

Entryinfo

Created: 03/26/2026 18:57
Updated: 03/26/2026 19:18
Changes: 03/26/2026 18:57 (66), 03/26/2026 19:18 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.