If a Chazan forgets Yaaleh Veyovo at Shacharis or Mincha - Shulchan Aruch HaRav 126:3-4 says that the Chazan can rely on his repetition of the Shemona Esrei for the forgotten Yaaleh Veyavo. If I am not mistaking this is the way Ashkenazim rule. (I do not know if the Sefardim rule the same or different).
What should a Chazan who is Davening Maariv on Chol Hamoed (when if Yaaleh Veyavo is forgotten one has to ray again) and forgot to say Yaaleh Veyavo do?
A: Repeat Shemona Esrei and make the Tzibur wait.
B: Say Kaddish and Aleinu and then say over Shemona Esrei.
C: Something else.