Svg Xmlns. SVG is mostly useful for vector type diagrams like Pie charts Two-dimensional graphs in an XY coordinate system etc. Waldyrious mentioned this issue Apr 25 2020.
SVG became a W3C Recommendation 14. Note that the namespace declaration only needs to be provided once on a root element. Its used to register a namespace prefix.
SVG stands for S calable V ector G raphics and it is a language for describing 2D-graphics and graphical applications in XML and the XML is then rendered by an SVG viewer.
The svg element is a container that defines a new coordinate system and viewport. That attack could potentially affect SVG files. But it is unrelated to the xmlns attribute. The xmlns attribute is required in XHTML invalid in HTML 401.