Jsdom is a JavaScript implementation of the W3C DOM, allowing developers to work with web page content in a Node.js environment. Comparing versions 0.8.3 and 0.8.4 reveals that at a high level the core functionalities and dependencies remain largely the same, with both versions relying on the same sub-modules such as cssom, request, cssstyle, nwmatcher, contextify, htmlparser2, and xmlhttprequest, suggesting a consistent feature set for parsing and manipulating HTML.
The primary distinction between the two versions resides in the release date, 0.8.4 coming out roughly three weeks after 0.8.3. This indicates that version 0.8.4 likely includes bug fixes, performance improvements, or minor enhancements rather than significant architectural changes. For developers, this means that upgrading from 0.8.3 to 0.8.4 should be a relatively safe operation. The similar dependency specifications further support this idea, showcasing stability in the underlying components.
For developers considering using jsdom, both versions offer a solid foundation for server-side DOM manipulation, enabling tasks such as web scraping, website testing, or building isomorphic applications. The library allows developers to load and interact with HTML content as if they were in a browser environment and that opens many functionalities for them. New users might find that the newer version is the best approach as it could contain less bugs. This is a low risk update so it should be prefered.
All the vulnerabilities related to the version 0.8.4 of the package
Server-Side Request Forgery in Request
The request package through 2.88.2 for Node.js and the @cypress/request package prior to 3.0.0 allow a bypass of SSRF mitigations via an attacker-controller server that does a cross-protocol redirect (HTTP to HTTPS, or HTTPS to HTTP).
NOTE: The request package is no longer supported by the maintainer.
form-data uses unsafe random function in form-data for choosing boundary
form-data uses Math.random() to select a boundary value for multipart form-encoded data. This can lead to a security issue if an attacker:
Because the values of Math.random() are pseudo-random and predictable (see: https://blog.securityevaluators.com/hacking-the-javascript-lottery-80cc437e3b7f), an attacker who can observe a few sequential values can determine the state of the PRNG and predict future values, includes those used to generate form-data's boundary value. The allows the attacker to craft a value that contains a boundary value, allowing them to inject additional parameters into the request.
This is largely the same vulnerability as was recently found in undici by parrot409 -- I'm not affiliated with that researcher but want to give credit where credit is due! My PoC is largely based on their work.
The culprit is this line here: https://github.com/form-data/form-data/blob/426ba9ac440f95d1998dac9a5cd8d738043b048f/lib/form_data.js#L347
An attacker who is able to predict the output of Math.random() can predict this boundary value, and craft a payload that contains the boundary value, followed by another, fully attacker-controlled field. This is roughly equivalent to any sort of improper escaping vulnerability, with the caveat that the attacker must find a way to observe other Math.random() values generated by the application to solve for the state of the PRNG. However, Math.random() is used in all sorts of places that might be visible to an attacker (including by form-data itself, if the attacker can arrange for the vulnerable application to make a request to an attacker-controlled server using form-data, such as a user-controlled webhook -- the attacker could observe the boundary values from those requests to observe the Math.random() outputs). A common example would be a x-request-id header added by the server. These sorts of headers are often used for distributed tracing, to correlate errors across the frontend and backend. Math.random() is a fine place to get these sorts of IDs (in fact, opentelemetry uses Math.random for this purpose)
PoC here: https://github.com/benweissmann/CVE-2025-7783-poc
Instructions are in that repo. It's based on the PoC from https://hackerone.com/reports/2913312 but simplified somewhat; the vulnerable application has a more direct side-channel from which to observe Math.random() values (a separate endpoint that happens to include a randomly-generated request ID).
For an application to be vulnerable, it must:
form-data to send data including user-controlled data to some other system. The attacker must be able to do something malicious by adding extra parameters (that were not intended to be user-controlled) to this request. Depending on the target system's handling of repeated parameters, the attacker might be able to overwrite values in addition to appending values (some multipart form handlers deal with repeats by overwriting values instead of representing them as an array)If an application is vulnerable, this allows an attacker to make arbitrary requests to internal systems.
tough-cookie Prototype Pollution vulnerability
Versions of the package tough-cookie before 4.1.3 are vulnerable to Prototype Pollution due to improper handling of Cookies when using CookieJar in rejectPublicSuffixes=false mode. This issue arises from the manner in which the objects are initialized.
Regular Expression Denial of Service
A Regular Expression vulnerability was found in nwmatcher before 1.4.4. The fix replacing multiple repeated instances of the "\s*" pattern.