mozilla / mozilla/pdf.js

[Bug]: Obsidian-exported PDFs have broken text inside highlighted boxes when viewed on Firefox

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#21,610 6 comments 0 reactions 1 assignee View on GitHub

@calixteman is already working on this.

Since Jul 21, 2026.

font-type3 regression upstream
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Description

Attach (recommended) or Link to PDF file

Parallelism-1.pdf

Web browser and its version

Firefox 152.0.6 (Build ID: 20260713164047)

Operating system and its version

Windows 11 24H2

PDF.js version

v6.1.200

Is the bug present in the latest PDF.js version?

Yes

Is a browser extension

No

Steps to reproduce the problem
  1. Open the attached PDF in latest firefox build or the online demo of PDF.js
  2. See the broken texts inside highlight boxes.
What is the expected behavior?
Image
What went wrong?
Image
Link to a viewer

No response

Additional context

I have been using Obsidian-exported PDFs with such highlight boxes in my classes for more than a year now and have only recently discovered this issue (I use firefox, but my classes use chrome/edge, so I may have been a bit late to pick up on this bug). I think it would be worth testing with the older versions of PDF.js, because I'm sure this used to render properly in firefox before.

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