in german the z and s sounds are switched. and you missed the actual z.
its Kurzgesagt (from the word "Kurz" (short) and the 3. person singular perfect of the verb "sagen" (to say), "gesagt" (said)).
(sorry but i couldn't not correct you and explain where the word came from)
Some minecraft mods had/have a similar problem. They use javas serialization stuff for sending stuff between client and server. There is mod that partially fixes this by only allowing whitelisted classes to be deserialized.
First of all, review it yourself. By reading it again and thinking about it you might find some stuff.
After that try static analysis tools like olap said (even some lsp (language server protocol) integrated in your editor can give you good tips).
Only after those two options i would even consider using llms, but finding a community of people that are about your language/framework can yield better results. Especially if it is a small project.
Yay, welcome to the team.
PS: Are you on !emacs@programming.dev already? Maybe with new people it will have more activity.