Currently, eZ Publish lacks support for svg images on the ezimage datatype. If you use an svg image on the ezimage attribute and try to publish, you will get an error:

The draft could not be stored.

Required data is either missing or is invalid:
Image: A valid image file is required.

Please enhance the ezimage datatype, so that svg files are supported. Alternatively, since svg files are not actually images but xml text descriptions for vectors that can be represented as images, a new datatype could be created.