Cardi B's Security Accused of Met Gala Beating

Cardi B's security team allegedly attacked an overzealous fan in the early hours of Tuesday morning, viciously punching and kicking him outside NYC's Met Gala ... TMZ has learned.

Law enforcement sources tell us the fan was trying to get an autograph from Cardi shortly after 2 AM as she left a post-Gala event at the Mark Hotel. In this video TMZ obtained, you can see Cardi tells the fan no ... but he persists, saying, "I'm an autograph hound." The next thing you see is a bunch of guys stomping someone on the ground.

The autograph seeker told cops, 3 security guards shoved him to the ground, and started the beatdown. We got video of the victim being transported, around 2:30 AM, by ambulance to a hospital where he was treated for neck and back pain.

Cardi was attending the Met Gala with her fiancé Offset, and the rest of Migos. They had left the scene by the time cops and paramedics arrived. At least one of the attackers in the video had been seen with Migos earlier in the evening.

NYPD is investigating. We have a call in to Cardi's team.