Nuxt versions 4.0.0 before 4.4.7 and 3.x before 3.21.7 accept protocol-relative paths such as //evil.com in the reloadNuxtApp function; these pass the script-protocol check but resolve to a cross-origin URL against the current page protocol. Attackers can inject paths like //evil.com to redirect users to attacker-controlled hosts, enabling phishing and OAuth authorization-code theft.