HOMEVULNERABILITIESCVE-2026-33438
MEDIUM

CVE-2026-33438

CWE-770Published: March 26, 2026· Updated: Mar 31, 2026

6.5
CVSS v3.1
EPSS:0.04%probability of exploitation in 30 daysPercentile:12.0th

Official 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.

NVD Source

Technical Analysis

CVE-2026-33438 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 6.5.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.Low
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected Vendors & Products

stirling1 product
stirling pdf
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://github.com/Stirling-Tools/Stirling-PDF/security/advisories/GHSA-3932-2rfq-87xm
ADVISORYhttps://github.com/Stirling-Tools/Stirling-PDF/security/advisories/GHSA-3932-2rfq-87xm

All References (2)

→
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

Quick Facts

CVE IDCVE-2026-33438
CVSS Score6.5 / 10
SeverityMEDIUM
WeaknessCWE-770
CISA KEVNo
EPSS (30d)0.04%
Affected1 vendor
PublishedMar 26, 2026

Related CVEs (CWE-770)

CVE-2026-12818
9.3
CVE-2026-42786
8.7
CVE-2026-35469
8.7
CVE-2026-32145
8.7
CVE-2026-43973
8.7
CVE-2026-48854
8.7

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-33438 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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