@Torrone
The /e/OS PDF viewer is forked from gsnathan’s and inherits its ~60 security issues. I’ve mentioned it here a handful of times over the past six months.
See also a 2021 thread touching on these same issues: Concerns and suggestions for system applications (Libre Office, PDF Viewer)
Along with this recent comment from Gaël: My /e/ exit interview - #15 by gael