Chrome was updated September 11
Matrix Element Desktop updated September 15, without a changelog or advisory. (The Element update on September 13 did not include the updated electron with the fix; today’s update does, according to their announcement on Matrix.)
Many/most electron apps don’t receive timely security updates, so if you don’t want arbitrary images to be able to get code execution you might want to stop using them.
Using a whole browser as the base for your application just seems unnecessary. Then again, I do most things from my terminal.
The web is basically becoming a whole operating system and I hate it.
At this pace I predict the fabled “year of the Linux desktop” will arrive when local- processing desktops have been overrun by closed-off mobile devices and cloud services.