CVE-2026-31938: parall jspdf Cross-site Scripting

Vulnerability summary

CVE-2026-31938 is a critical (CVSS 9.6) Cross-site Scripting vulnerability in parall jspdf. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.8% of scored vulnerabilities.

Timeline

1. 18-03-2026
   PublishedVulnerability first disclosed.
2. 07-09-2026
   Last modifiedVulnerability information updated.

Description

jsPDF is a library to generate PDFs in JavaScript. Prior to version 4.2.1, user control of the `options` argument of the `output` function allows attackers to inject arbitrary HTML (such as scripts) into the browser context the created PDF is opened in. The vulnerability can be exploited in the following scenario: the attacker provides values for the output options, for example via a web interface. These values are then passed unsanitized (automatically or semi-automatically) to the attack victim. The victim creates and opens a PDF with the attack vector using one of the vulnerable method overloads inside their browser. The attacker can thus inject scripts that run in the victims browser context and can extract or modify secrets from this context. The vulnerability has been fixed in jspdf@4.2.1. As a workaround, sanitize user input before passing it to the output method.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.