GHSA-786w-p5pm-cvgh: phpsysinfo/phpsysinfo (CVE-2026-55584)

Package	Ecosystem	Affected	Fixed in
phpsysinfo/phpsysinfo	Packagist	<3.4.6	3.4.6

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The phpsysinfo/phpsysinfo Packagist package, versions before 3.4.6, has an IP allowlist (PSI_ALLOWED) that can be bypassed because the access check trusts the X-Forwarded-For and Client-IP request headers over the actual remote address. A remote attacker with no account can send a spoofed header matching an allowed address and read the full system information the application exposes, such as hostname, kernel version, memory layout, and network interface addresses. Upgrade to version 3.4.6, which is the listed fixed version.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
7.5	High	3.1	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.019, the 80th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:07 UTC First seen by agentprime
31 Oct 2026, 14:07 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.