Methods, systems, and devices for detection of illegal commands are described. A memory device, such as a dynamic random access memory (DRAM), may receive a command from a device, such as a host device, to perform an access operation on at least one memory cell of a memory device. The memory device may determine, using a detection component, that a timing threshold associated with an operation of the memory device would be violated by performing the access operation. The memory device may refrain from executing the access operation based on determining that performing the access operation included in the command would violate the timing threshold. The memory device may transmit, to the device, an indication that performing the command would violate the timing threshold.