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Javascript in Firefox 90 PDF form viewer

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  • Last reply by fuffberry

fuffberry
fuffberry
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As of Firefox 90, the PDF viewer within Firefox is reported to handle Javascript in PDFs. What must be done to disable JAVASCRIPT within the PDF viewer?

As of Firefox 90, the PDF viewer within Firefox is reported to handle Javascript in PDFs. What must be done to disable JAVASCRIPT within the PDF viewer?

Chosen solution

Here's how:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box in the page, type or paste pdfjs.enableScripting and pause while the list is filtered

(3) Double-click the preference to switch the value from true to false

I'm not sure how to test that it worked. Maybe Adobe has a safe example on their website?

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All Replies (5)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
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Chosen Solution

Here's how:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box in the page, type or paste pdfjs.enableScripting and pause while the list is filtered

(3) Double-click the preference to switch the value from true to false

I'm not sure how to test that it worked. Maybe Adobe has a safe example on their website?

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
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By the way, it was false up to Firefox 87 and flipped to true starting in Firefox 88.

cor-el
cor-el
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I only see that pref set to true in Nightly.

  • 1702796 - Update pdf.js to version 2.8.320
    • #13116 Enable scripting by default in the viewer (PR 13053 follow-up)

Modified by cor-el

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
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I wonder whether this one overrides that one?

https://searchfox.org/mozilla-release/source/modules/libpref/init/all.js#343

fuffberry
fuffberry Question owner
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Thanks for the info - It was Firefox 88 release notes where I saw the bit about JAVASCRIPT in PDFs. I wish I could change the title on this issue to say "Javascript in Firefox 88 PDF form viewer" - upgraded my test system to FF90 then upgraded 'production' to FF88. Usually my questions are associated with the test 'nightly' version. I overlooked it when nightly went to version 88.