Firefox 88
Until Firefox 87, Mozilla blocked the implementation of JavaScript code in the built-in PDF viewer; This has changed with version 88.
Mozilla has built-in JavaScript support in Firefox 88’s PDFs and automatically activates the feature. So turn it off again.
In mid-April 2021, Mozilla released version 88 of its Firefox browser. The update brought a number of security and privacy improvements. The innovations also include support for JavaScript in PDFs, which is now turned on by default. That is, Firefox executes the JavaScript code found in the PDF files you see in the browser. This may be useful for some use cases, such as checking the entered form data or making changes to the document based on the data. On the other hand, activated JavaScript also poses a risk – hackers can use it to execute malicious code. If you want to reduce these security risks and do not need the feature in Firefox PDF Viewer, simply deactivate it. COMPUTER BILD explains how to do this.
Download Firefox for Windows
Download Firefox for Mac
Firefox: JavaScript in PDFs ausschalten
By clicking the switch with the two arrows, you launch JavaScript for PDFs (Real) And from (False).
There is no option to deactivate JavaScript in Firefox’s “regular” settings. Instead, you have to make a change to the advanced settings. How to do it:
- handle About: config In the address line and hit Enter.
- Confirm, press Accept the risk and carry on.
- Click in the search box above pdfjs.enable a.
- Toggle the option corresponding to “False” by clicking on the arrow button at the end of the line.
Going forward, Firefox ignores the JavaScript code included in PDF files. If you need the function at a later time, just activate it again by returning the above option to “true”. More information about browser script language and how to deactivate JavaScript in Firefox, Chrome, Edge, and Opera can be found in a separate advisor at COMPUTER BILD.
“Certified gamer. Problem solver. Internet enthusiast. Twitter scholar. Infuriatingly humble alcohol geek. Tv guru.”
