Not sure why you only mention Chromium and Firefox in the post text, I can only assume this vulnerability affects ALL browsers. Safari (WebKit based) is, as far as I know, the second most used browser in the world.
Actually, it’s specific to libwebp, but many things that decode webp just use this library (for example, decoding webp with the "image" rust crates doesn’t use libwebp. It does use it for encoding thought).