The React Developer Tools extension registers a message listener with window.addEventListener('message', ) in a content script that is accessible to any webpage that is active in the browser. Within the listener is code that requests a URL derived from the received message via fetch(). The URL is not validated or sanitised before it is fetched, thus allowing a malicious web page to arbitrarily fetch URL’s via the victim's browser.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-5654
• https://gist.github.com/CalumHutton/1fb89b64409570a43f89d1fd3274b231
• facebook/react#27417
• facebook/react@09285d5
• facebook/react@94d5b5b