Annotations for the 5k image 'minival' subset of COCO val2014 can be found at https://dl.dropboxusercontent.com/s/o43o90bna78omob/instances_minival2014.json.zip?dl=0.
Annotations for COCO val2014 (set) minus minival (~35k images) can be found at https://dl.dropboxusercontent.com/s/s3tw5zcg7395368/instances_valminusminival2014.json.zip?dl=0.