Font rendering is incredibly complex, perhaps one of the most complex things in computer software.
It already required execution of a virtual machine:
> TrueType systems include a virtual machine that executes programs inside the font, processing the "hints" of the glyphs, in TrueType called “instructions”. These distort the control points which define the outline, with the intention that the rasterizer produce fewer undesirable features on the glyph.
Now it just _also_ requires potential execution of arbitrary WASM code, too.
It already required execution of a virtual machine:
> TrueType systems include a virtual machine that executes programs inside the font, processing the "hints" of the glyphs, in TrueType called “instructions”. These distort the control points which define the outline, with the intention that the rasterizer produce fewer undesirable features on the glyph.
Now it just _also_ requires potential execution of arbitrary WASM code, too.