CVE-2026-103592

simple-php-router through 5.4.1.7 contains an IP restriction bypass vulnerability in the IpRestrictAccess middleware that allows remote unauthenticated attackers to bypass IP whitelist and blacklist protections. Attackers can spoof X-Forwarded-For, CF-Connecting-IP, or Client-IP headers to impersonate whitelisted addresses or evade blacklists, gaining access to IP-restricted routes.

• https://github.com/skipperbent/simple-php-router
• https://github.com/skipperbent/simple-php-router/blob/5.4.1.7/src/Pecee/Http/Middleware/IpRestrictAccess.php
• https://github.com/skipperbent/simple-php-router/blob/5.4.1.7/src/Pecee/Http/Request.php
• https://github.com/skipperbent/simple-php-router/issues/727
• https://www.vulncheck.com/advisories/simple-php-router-through-5.4.1.7-ip-restriction-bypass-via-forwarding-headers