Techniques for enabling secure cross-process memory sharing are provided. In one set of embodiments, a first user process executing on a computer system can create a memory handle representing a memory space of the first user process. The first user process can further define one or more access restrictions with respect to the memory handle. The first user process can then transmit the memory handle to a second user process executing on the computer system, the memory handle enabling the second user process to access at least a portion of the first process' memory space, subject to the one or more access restrictions.