CVE-2026-17545

High

Description

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.

SeverityHigh

CVSS7.5

Exploit probability—

Product

Php

PublishedSep 25, 2026

First seenSep 25, 2026

Weakness typeCWE-67CWE-67

How to fix

Update

php php8.2.34, 8.3.35, 8.4.26, 8.5.11 or later

Vendor advisories

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

Affected products

Product	Affected versions	Fixed in
php php	8.2.0 ≤ v < 8.2.34, 8.3.0 ≤ v < 8.3.35, 8.4.0 ≤ v < 8.4.26, 8.5.0 ≤ v < 8.5.11	8.2.34, 8.3.35, 8.4.26, 8.5.11

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