According to Zach Galligan, who starred in the original film and its sequel, Warner Bros. is actively working on the third installment of the franchise.
"After 35 years, they finally birthed a script," the actor noted, as reported by Variety. According to Galligan, everyone's now just waiting for the script to get approval from Steven Spielberg, who's serving as executive producer on "Gremlins 3."

Source:
imdb