An Improper Check for Unusual or Exceptional Conditions in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS Evolved on PTX10003 Series allows an unauthenticated adjacent attacker to cause an impact to the integrity of the system. When specific transit MPLS packets are received by the PFE, these packets are internally forwarded to the RE. This issue is a prerequisite for CVE-2023-44195. This issue affects Juniper Networks Junos OS Evolved: * All versions prior to 20.4R3-S8-EVO; * 21.1-EVO version 21.1R1-EVO and later; * 21.2-EVO versions prior to 21.2R3-S6-EVO; * 21.3-EVO version 21.3R1-EVO and later; * 21.4-EVO versions prior to 21.4R3-S3-EVO; * 22.1-EVO versions prior to 22.1R3-S4-EVO; * 22.2-EVO versions prior to 22.2R3-S3-EVO; * 22.3-EVO versions prior to 22.3R2-S2-EVO, 22.3R3-EVO; * 22.4-EVO versions prior to 22.4R2-EVO.