A vulnerability in a specific loopback filter action command, processed in a specific logical order of operation, in a running configuration of Juniper Networks Junos OS, allows an attacker with CLI access and the ability to initiate remote sessions to the loopback interface with the defined action, to hang the kernel. Affected releases are Juniper Networks Junos OS 12.1X46 prior to 12.1X46-D55; 12.3X48 prior to 12.3X48-D35; 14.1 prior to 14.1R8-S4, 14.1R9; 14.1X53 prior to 14.1X53-D40; 14.2 prior to 14.2R4-S9, 14.2R7-S8, 14.2R8; 15.1 prior to 15.1F5-S3, 15.1F6, 15.1R4; 15.1X49 prior to 15.1X49-D60; 15.1X53 prior to 15.1X53-D47; 16.1 prior to 16.1R2. No other Juniper Networks products or platforms are affected by this issue.