Leaker @momomo_us recently posted an image showing a CPU socket cover marked for LGA-18xx, although since it's also marked with LGA-17xx, it's likely that both sockets might end up being closely related. This isn't the first time we're hearing about Intel's next socket coming down the pipeline. Igor'sLAB hinted at it before with a look at a new mounting system that would work with both LGA-1700 and -1800, indicating some similarity there, as well.
Most importantly, this clarifies the sockets in question being Intel's, as without further clarification "LGA-17xx" could also have referred to AMD's AM5 socket, which was leaked to have 1718 pins as part of the switch from a PGA to an LGA setup.
Just when we'll be getting to see this new socket in action is uncertain. The already-upcoming LGA-1700 socket is set to be used for both 12th-gen Core "Alder Lake" parts and "Raptor Lake" after that.
Rumors have also suggested that it might stay for next-generation "Meteor Lake" CPUs after that, and its substantial 500-pin increase over LGA-1200 may offer a degree of future proofing.
If Meteor Lake, which is set to be Intel's first 7 nm product, were to stay on LGA-1700, that would likely push the boat for LGA-1800 adoption out to early 2023, although at that point leaks begin to become scarce and crystal balls start to become cloudy as a result.