parallax jsPDF up to 4.0.x Node.js addJS race condition

Summaryinfo

A vulnerability labeled as critical has been found in parallax jsPDF up to 4.0.x. This issue affects the function addJS of the file Node.js. Executing a manipulation can lead to race condition. The identification of this vulnerability is CVE-2026-24040. The attack may be launched remotely. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in parallax jsPDF up to 4.0.x. This vulnerability affects the function addJS of the file Node.js. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

jsPDF is a library to generate PDFs in JavaScript. Prior to 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 [email protected].

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-24040 since 01/20/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

Upgrading to version 4.1.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 2863e5c26afef211a545e8c174ab4d5fce3b8c0e is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0553). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Red Hat Enterprise Linux
• HCL BigFix

Productinfo

Vendor

• parallax

Name

• jsPDF

Version

• 4.0

License

• open-source

Website

• Product: https://github.com/parallax/jsPDF/

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion