CVE-2026-55584 HIGH

CVE-2026-55584: phpSysInfo: IP allowlist (PSI_ALLOWED) bypass via spoofed X-Forwarded-For / Client-IP headers

Vendor Phpsysinfo
Product phpsysinfo
Weakness CWE-290
Published August 28, 2026
Last update August 28, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

August 28, 2026 CVE published

Related vulnerabilities

04Related CVE