{"id":"CVE-2026-56709","title":"Grav before 3.9.2 fails to validate untrusted Host headers in the sendInvitationEmail() function when constructing token-bearing invitation links","summary":"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 …","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-350"],"published":"2026-08-25","updated":"2026-10-12","sourceUpdated":"2026-10-12T15:10:00.207","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-56709","references":[{"url":"https://github.com/getgrav/grav/security/advisories/GHSA-69vf-mjxw-x79j","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/grav-before-host-header-injection-via-sendinvitationemail","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"epss":0.00434,"epssPercentile":0.35852,"ingestedAt":"2026-10-12T15:55:08.146Z","slug":"CVE-2026-56709","body":"## Overview\n\nGrav 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}