CVE-2026-33438
Stirling-PDF vulnerable to DoS via add-watermark
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Stirling-PDF vulnerable to DoS via add-watermark
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.
- Record
CVE-2026-33438- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
EUVDEUVD-2026-16262
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.
- Record
EUVD-2026-16262- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-33438- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
OSV
Stirling-PDF vulnerable to DoS via add-watermark
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.
- Record
CVE-2026-33438- CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-770
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-33438 is a medium vulnerability (CVSS 6.5) in Stirling Pdf, published March 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 35th percentile. No source names a fixed version.