CVE-2026-17545

On Windows, PHP's filesystem and stream APIs do not reject reserved device names such as CON, PRN, AUX, NUL, COM1 to COM9, LPT1 to LPT9, CONIN$ and CONOUT$ when they appear as a component of a path. An attacker-controlled filename therefore reaches CreateFileW() and opens a device instead of the regular file the application expected, which can block or hang the request and exhaust worker processes.

Score

CVSS 3.1 7.5 High

Status

Analyzed - security@php.net

Published

2026-09-25

Last modified

2026-10-23

Weaknesses

CWE-67

Affected products

• Php (Php)
• Php (Php Group)

References

• https://github.com/php/php-src/security/advisories/GHSA-9f67-6fw4-hpfp