CVE-2026-55584

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.

  • Published Aug 28, 2026
  • CVSS 7.5 high
  • 1.9% chance of exploitation in the next 30 days (EPSS)
  • Public exploit code is available
  • A fix is available

Affected software

CVE-2026-55584 at the National Vulnerability Database