Quake 3 engine, as used in multiple games, allows remote attackers to cause a denial of service (client disconnect) via a long message, which is not properly truncated and causes the engine to process the remaining data as if it were network data.
Buffer overflow in the G_Printf function in Star Wars Jedi Knight: Jedi Academy 1.011 and earlier allows remote attackers to execute arbitrary code via a long message using commands such as (1) say and (2) tell.