CVE-2026-56709 [HIGH] – Grav before 3.9.2 fails to validate untrusted Host headers in the sendInvitationEmail() fu

Grav before 3.9.2 fails to validate untrusted Host headers in the sendInvitationEmail() function when constructing token-bearing invitation links. Attackers can manipulate the Host header to poison invitation links and redirect users to attacker-controlled domains, bypassing the require_trusted_host protection which only covers password reset flows.