I was watching Airport Security Colombia, and sharp objects were mentioned (I know that because of the subtitles). They said something like "cortopozantes", but I can't find anything like that on Google.
The word you heard is cortopunzante and is used in some South American countries. There is also the word punzocortante, which is mostly used in Central American countries and Mexico, as reflected by the official RAE dictionary.
In Spain, the Iberia site lists:
Armas u objetos punzantes o con aristas
(arms, sharp pointed objects or with edges).
Objetos Punzantes o Cortantes
(sharp pointed or cutting objects).
Note that these are more or less technical terms used in legal, medical, or police jargon. A general term for sharp object would be:
Objeto con filo