CVE-2026-128023 PUBLISHED

FrankenPHP before 1.13.0 Authentication Bypass via Dot-Form Header Name Aliasing

Assigner: VulnCheck
Reserved: 12.11.2026 Published: 13.11.2026 Updated: 13.11.2026

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.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS Score: 9.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS Score: 7.4

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	php
Product	frankenphp
Versions	Default: unaffected affected from 0 to 1.13.0 (excl.) Version 1.13.0 is unaffected

CVE-2026-128023 PUBLISHED

FrankenPHP before 1.13.0 Authentication Bypass via Dot-Form Header Name Aliasing

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Product Status

Credits

References

Problem Types