CVE-2026-55584: Phpsysinfo

High severity, CVSS 7.5. EPSS: 1.9% chance of exploitation in the next 30 days.

phpSysInfo is a customizable PHP script that displays system information. Prior to 3.4.6, the PSI_ALLOWED access-control check in read_config.php trusts attacker-controlled X-Forwarded-For and Client-IP HTTP headers before REMOTE_ADDR. A remote unauthenticated attacker can supply an allowed address in one of these headers to impersonate a trusted client and access exposed hostname, kernel, CPU, memory, filesystem, and network-interface information. This issue is fixed in version 3.4.6.

Affected products

• Phpsysinfo Phpsysinfo: before 3.4.6 (fixed in 3.4.6)

Published 2026-08-28. Last modified 2026-09-09.