On SRX Series devices, a crafted ICMP packet embedded within a NAT64 IPv6 to IPv4 tunnel may cause the flowd process to crash. Repeated crashes of the flowd process constitutes an extended denial of service condition for the SRX Series device. This issue only occurs if NAT64 is configured. Affected releases are Juniper Networks Junos OS 12.1X46 prior to 12.1X46-D71, 12.3X48 prior to 12.3X48-D55, 15.1X49 prior to 15.1X49-D100 on SRX Series. No other Juniper Networks products or platforms are affected by this issue.