The comment you’re replying to is misleading. SVG supports JavaScript but only if you load the SVG directly in your browser or inline it fully into the DOM. Using it as a normal image tag, by reference or with inlined data:, it’s inert and harmless from a JavaScript perspective.

However, for a long time browsers were susceptible to denial of service attacks from maliciously crafted XML files, which SVG could exploit. (“Million laughs”). This doesn’t work in current versions but it might be a reason that SVGs are rejected.