Which is the safest server-side language for the web? Which languages have security problems?

Question

server-side languages

Answer 1

I know I'm late, but the answer here is completely wrong. Neither HTML, nor CSS are server-side.
About security: There is no secure language. You write the code, you tell the code what to do. If you fail to make it secure you failed.

Answer 2

CSS and HTML. Any program may have security problems with no respect to lang. Take a look at any lang bugtrackers and ensure :)