A Cross-site Scripting (XSS) vulnerability in the J-Web component of Juniper Networks Junos OS allows an unauthenticated attacker to run malicious scripts reflected off of J-Web to the victim's browser in the context of their session within J-Web. This issue affects Juniper Networks Junos OS all versions prior to 19.1R3-S9; 19.2 versions prior to 19.2R3-S6; 19.3 versions prior to 19.3R3-S7; 19.4 versions prior to 19.4R2-S7, 19.4R3-S8; 20.1 versions prior to 20.1R3-S5; 20.2 versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S5; 20.4 versions prior to 20.4R3-S4; 21.1 versions prior to 21.1R3-S4; 21.2 versions prior to 21.2R3-S1; 21.3 versions prior to 21.3R3; 21.4 versions prior to 21.4R2; 22.1 versions prior to 22.1R2.