FrankenPHP before 1.13.0 contains an authentication bypass vulnerability that allows unauthenticated attackers to spoof trusted headers by sending dot-form header names that PHP rewrites to underscores. Attackers can send headers like X.Authenticated.User or X.Forwarded.For that map to $_SERVER keys, spoofing user identity, client IP, or scheme.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-290"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/128xxx/CVE-2026-128023.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.13.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}