CVE-2026-85733: FrankenPHP: Docker images serve phpinfo() as the default index.php, leaking environment variables

Description

FrankenPHP is a modern application server for PHP. Prior to 1.12.5, the official FrankenPHP Debian and Alpine Docker images include a default /app/public/index.php that executes phpinfo(). A derived image that does not overwrite this placeholder serves the diagnostics page in production and can disclose environment variables used for secrets, PHP configuration directives, loaded extensions, software versions, and system paths. Images built using the documented pattern with their own /app/public/index.php are not affected, and already derived images must be rebuilt or supplied with an application index to remove the exposed placeholder. This issue is fixed in version 1.12.5.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack vector

Network

Complexity

Low

Privileges

None

User interaction

None

Confidentiality

Low

Integrity

None

Availability

None

Scope

Unchanged

Exploitation

Is it being used?

Exploit prediction (EPSS)0.2% · higher than 16% of CVEs

Exploited in the wildNo evidence yet

CISA KEVNot listed

Ransomware campaign useNot known

Affected products

Which versions

PH

PHP · PHP

< 1.12.5 · source: vendor