According to Yahoo,
The big crossover between The CW’s “Riverdale” and the Netflix series “Chilling Adventures of Sabrina” is finally happening!
“We’ve been talking about having Sabrina visit Riverdale since Season 1, so it’s thrilling that this is finally happening, as part of our ‘Rivervale’ special event,” showrunner Roberto Aguirre-Sacasa told EW in a statement. “It’s also perfect that she shows up to help Cheryl Blossom during her hour of greatest need. Everyone on set lost their minds — I think fans will, too. It’s really fun and special.”
“Sabrina” star Kiernan Shipka also confirmed the news with an Instagram post from the set of “Riverdale,” reprising her “Chilling” role after the Netflix series was abruptly cancelled.
Shipka will appear in “Riverdale” Season 6 Episode 4, which is titled “The Witching Hour(s)” and finds Cheryl (Madelaine Petsch) performing a dangerous spell. The question now is how Shipka’s Sabrina character appears, given where things left off in the series finale – although it’s possible the events of “Riverdale” take place earlier than the events of “Chilling Adventures of Sabrina.”
“Sabrina” officially crossed over into the world of “Riverdale” in a Season 3 episode that saw Shipka’s character visiting a maple tree owned by Cheryl’s family, but no “Riverdale” characters appeared.
The CW hasn’t yet set a premiere date for “Riverdale” Season 6