Just call it sheer audacity.

Riley Keough came dangerously close to breaking the Cannes Film Festival dress code Thursday night, attending the “Histoires Parallèles (Parallel Tales)” premiere in sheer Chanel Haute Couture.

Comprised of a collarless jacket, midi skirt and top — all crafted from nude-hued organza embellished with beads and pearls — the see-through ensemble allowed the actress’ pale blue lingerie to peek through.

While the silhouette may have been conservative, the fest famously banned body-baring styles in 2025.

“Nudity is prohibited on the red carpet, as well as in any other area of the festival,” according to the updated Cannes rules.

Also a no-go? Gowns that span the full length of the step-and-repeat, previously a popular choice at the event.

“Voluminous outfits, in particular those with a large train, that hinder the proper flow of traffic of guests and complicate seating in the theater are not permitted,” the charter reads.

Keough, 36, isn’t the only star who’s tested the limits of the Cannes dress code since regulations changed, however.

At last year’s festival, her fellow Chanel ambassador Kristen Stewart selected a pink tweed short suit styled with a sheer skirt, while Heidi Klum turned heads in a floral Elie Saab gown with a dramatic train at the opening ceremony.

Jury member Halle Berry, meanwhile, was forced to “pivot” from a voluminous Gaurav Gupta dress to a sleeker, striped Jacquemus number for the same red carpet event.