Dispatcher reported a flight over Central Asia experienced possible GPS jamming causing them to divert.

Narrative

At the beginning of my shift; I was advised that Aircraft X was having GPS signal issues; that had apparently started when the flight was over Central Asia earlier in the flight. The Captain had advised that the Actual Navigation Performance (ANP) that was available from the GPS was at approximately 15 to 16 nm; which was not acceptable for Minimum Navigation Performance Specifications (MNPS) entry. Starting at approximately XA20; maintenance was patched into the flight on Satcom by Dispatch; and several restoration procedures were examined to attempt to fix the issue. In addition to this; management was consulted as to what options would be favorable if the issue could not be rectified. This included proceeding onwards at 29000 ft. below the MNPS airspace to a fuel stop in ZZZZ or ZZZZ1.After it was determined that the problem could not be fixed; several European diversion airports were considered. While ZZZZ2 did have the curfew in effect until XE00 local; it was decided that it would be the best diversion point for the flight and that the flight would hold for the curfew to end while burning off excess fuel to avoid an overweight landing. At approximately XB25; I amended the release with the flight crew to change the destination to ZZZZ2; and advised that they should plan on holding to avoid curfew and reduce landing weight. The flight landed a few minutes after the end of my scheduled shift without incident; and the flight was schedule to depart from ZZZZ2 to ZZZ in a different aircraft with new crew.This was a new issue for this flight that has not been seen before. The causes for the loss of GPS accuracy are currently unknown; though recent GPS jamming activity over the Middle East/Central Asia may play a role. New restorative procedures for GPS after a signal loss event may be preventative.