Firefox 88 Enables JavaScript Embedded In PDFs By Default 100

In addition to the other weird things PDF files can contain, one of them is JavaScript. Putatively offered as a way to create self-validating forms, this scripting capability has been abused over the decades in just about every way you can imagine. Firefox's built-in viewer, although it has apparently had the ability to execute embedded JS for some time, never turned that feature on, making it a safe(r) way to open PDFs... Until now.

To turn off JavaScript execution in PDFs: Enter about:config in the address bar; click "I'll be careful." In the search box near the top, enter pdfjs.enableScripting. Change the setting to False. Close the page.