On Juniper Networks Junos OS 15.1 releases from 15.1R3 to 15.1R4, 16.1 prior to 16.1R3, on M/MX platforms where Enhanced Subscriber Management for DHCPv6 subscribers is configured, a vulnerability in processing IPv6 ND packets originating from subscribers and destined to M/MX series routers can result in a PFE (Packet Forwarding Engine) hang or crash.
https://kb.juniper.net/JSA10786