'Avengers: Doomsday' trailer causes chaos behind closed doors at CinemaCon

Marvel’s first 'Avengers: Doomsday' trailer debut reportedly came with tight security

Marvel reportedly enforced intense security during the first Avengers: Doomsday trailer screening at CinemaCon, as the studio worked to stop any footage from leaking online.

The highly anticipated preview was shown during Disney’s closed-door panel in Las Vegas, where Marvel president Kevin Feige appeared alongside Joe Russo, Anthony Russo, and Chris Evans.

According to journalist Jacob Fisher, security came down hard on attendees who tried to film the unreleased trailer, with several people reportedly removed from the presentation.

For anyone hoping for the DOOMSDAY trailer to be leaked, security came down hard & took a few ppl away who tried to record.

Security here is unmatched.

— Jacob (@JacobFisherDF) April 17, 2026

Marvel’s strict no-recording policy appears to have worked, as no leaked video has surfaced despite massive demand from fans online.

Even so, detailed descriptions of the footage quickly spread across social media. Attendees claimed the trailer featured Steve Rogers wielding Mjolnir again, Thor battling Doctor Doom, and major crossovers involving the Avengers, X-Men, and Fantastic Four.

Other reported moments included Shang-Chi fighting Gambit and Mystique transforming into Yelena Belova, hinting at a huge multiverse storyline.

With the footage still locked away, fans may need to wait for an official release to see it for themselves.

Avengers: Doomsday is set to hit theaters on December 18, 2026.