As the U.S. turns its back on security commitments, Germany faces a profound shift in its post-war defense policy. Can it still rely on France and the UK?
Germany is at a crossroads when it comes to its security policy — one of the deepest upheavals of the post-War era.
Member states already have mutual defense pacts that overrule any competing EU dictates in time of war.
https://en.m.wikipedia.org/wiki/Common_Security_and_Defence_Policy
So Hungary can veto whatever they want, but defensive actions will be taken regardless.