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Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVE-2026-24040

Medium
6.3/10

Summary

jsPDF is a library to generate PDFs in JavaScript. Prior to version 4.1.0, the "addJS" method in the jspdf Node.js build utilizes a shared module-scoped variable (text) to store JavaScript content. When used in a concurrent environment (e.g., a Node.js web server), this variable is shared across all requests. If multiple requests generate PDFs simultaneously, the JavaScript content intended for one user may be overwritten by a subsequent request before the document is generated. This results in Cross-User Data Leakage, where the PDF generated for User A contains the JavaScript payload (and any embedded sensitive data) intended for User B. Typically, this only affects server-side environments, although the same race conditions might occur if jsPDF runs client-side. The vulnerability has been fixed in jsPDF 4.1.0.

  • HIGH
  • NETWORK
  • LOW
  • UNCHANGED
  • NONE
  • NONE
  • LOW
  • NONE

CWE-362 - Race Condition

A race condition occurs in a shared memory program when two threads/processes access the same shared memory data, and at least one thread executes a write operation. This vulnerability manipulates the time to check vs. time to use (TOC/TOU) gap between the threads in the critical section to cause disorientation in the shared data. The impact can vary from compromising the confidentiality of the system to causing the system to crash or to execute arbitrary code.

References

Advisory Timeline

  • Published