Brunt is said to have confronted an official as the players exited the field of play following West Brom's 2-0 quarter-final defeat at Villa Park.
A statement on West Brom's official website on Friday read: "The midfielder will continue to be available for selection, including tomorrow's Barclays Premier League clash against Stoke, until a date for the hearing is finalised. Brunt has accepted the charge.
"The 30-year-old is alleged to have used abusive and/or insulting words and/or behaviour towards a Match Official, in or around the tunnel area after the end of Albion's FA Cup quarter-final tie at Aston Villa on Saturday, March 7."
Villa's victory - secured thanks to goals from Fabian Delph and Scott Sinclair - was marred by a pitch invasion that saw thousands of fans spill onto the field at full-time.
A number of supporters had earlier encroached onto the playing surface following Sinclair's 85th-minute effort and during stoppage time.
