Certain types of malformed Path Computation Element Protocol (PCEP) packets when received and processed by a Juniper Networks Junos OS device serving as a Path Computation Client (PCC) in a PCEP environment using Juniper's path computational element protocol daemon (pccd) process allows an attacker to cause the pccd process to crash and generate a core file thereby causing a Denial of Service (DoS). Continued receipt of this family of malformed PCEP packets will cause an extended Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1F6-S13, 15.1R7-S4; 15.1X49 versions prior to 15.1X49-D180 on SRX Series; 15.1X53 versions prior to 15.1X53-D238, 15.1X53-D496, 15.1X53-D592; 16.1 versions prior to 16.1R7-S4; 16.2 versions prior to 16.2R2-S9; 17.1 versions prior to 17.1R2-S11, 17.1R3; 17.2 versions prior to 17.2R1-S9; 17.2 version 17.2R2 and later prior to 17.2R3-S2; 17.3 versions prior to 17.3R3-S3; 17.4 versions prior to 17.4R2-S2, 17.4R3; 18.1 versions prior to 18.1R3-S2; 18.2 versions prior to 18.2R2-S6, 18.2R3; 18.2X75 versions prior to 18.2X75-D40; 18.3 versions prior to 18.3R2; 18.4 versions prior to 18.4R1-S2, 18.4R2. This issue does not affect releases of Junos OS prior to 15.1R1.