The full cruise control system is described in the Owner's Manual - for my 2014 ES it is 3-7 to 3-10. Other models may differ, just check your index.
The system has a Self-diagnosis device. When the system indicator light flashes, this suggests the diagnostics has seen an irregularity. I assume you are not also seeing the display showing an error code too?
Most times the problem seems to be the rear brake light switch, situated behind the right footrest heel plate. Hence yoyo's suggestion. Wierd things can happen with the switch, which sends power to the rear brake lights & talks to the cruise system. It is well worth dropping the heel plate off & checking the switch for any obvious damage, as well as checking the wiring/connectors. It is always possible that road debris has damaged the switch/wiring too.
Aside from that, there are several other possibilities, but let's have you look at the most likely source first
Ride Safe .............................. KEN