CBS Corp. (CBS - Get Report) is having a family feud. 

A judge in Delaware granted CBS a restraining order against Shari Redstone on Wednesday, May 16. The restraining order will be in place until the judge can make a decision about stock dilution.

On Monday, CBS's board voted to sue National Amusements Inc., which is its parent company. CBS has sued to dilute the voting power of Redstone, who runs NAI, because Redstone is attempting to force a merger between CBS and Viacom Inc. (VIA - Get Report) . Currently, Redstone holds the majority voting power for both Viacom and CBS. 

CBS believes that Redstone would replace the board and possibly the CEO, which has led them to sue.

The board vote was originally scheduled for Thursday, but has been postponed.

CBS was up slightly in after hours trading, but Viacom held steady.