Methods, systems, and computer program products for providing zero-copy multiplexing using copy-on-write are disclosed. Examples generally relate to both physical and virtualized computer systems. A computer-implemented method may include receiving notification of an incoming network packet, determining that a section of the network packet is to be modified, creating a copy of the network packet section to be modified, modifying the network packet section copy, and sending a memory location of the modified network packet section copy to an application. In a virtualized computer system, a hypervisor may receive notification of an incoming network packet, determine that a section of the network packet is to be modified, create a copy of the network packet section to be modified, modify the network packet section copy, and send a memory location of the modified network packet section copy to a guest when providing a modified network packet to the guest.