Grav CMS before 2.0.16 contains an origin validation bypass in the Uri::referrer() and Pages::referrerRoute() methods, which validate the Referer header using an unanchored string prefix match (str_starts_with($referrer, $base)) with no trailing delimiter. An attacker who controls a domain that begins with the victim site's origin (e.g. https://example.com.attacker.tld) can send a request with such a Referer to be treated as same-origin, bypassing the Referer-based origin check.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-346"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72702.json"
}