The Hollywood Reporter:

Annette Bening is signing on for her first comic book movie.

The four-time Oscar nominee is joining Brie Larson in Captain Marvel, Marvel Studios’ first female-led feature film.

Oh, cool! Adds to the “Prestige Actor in Marvel Studios” hall, alongside Glenn Close, Michael Douglas and Robert Redford. But who is she playing?

Details on Bening’s character are being kept hidden deep in the Kree Empire, but "scientist" is said to be in her job description.
Oh, that's the sentence which will launch a thousand clickbait articles.