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CVE-2026-55584

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

Published: Aug 28, 2026Updated: Aug 31, 2026 Sources: CVE List NVDCWE-290
7.5HIGH
NVD MITRE
EPSS Score
2.4%
Top 16.9%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available
Self-Check
Not available

Description

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-290

Affected Products

phpsysinfo
oss-project
phpsysinfoOn-prem
Web & CMS Plugins / cms-core

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Initial Access
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References

https://github.com/phpsysinfo/phpsysinfo/commit/019fa2d7e568ea11461adb4bd33da5dc87c4b9ab
github.com
https://github.com/phpsysinfo/phpsysinfo/releases/tag/v3.4.6
github.com
https://github.com/phpsysinfo/phpsysinfo/security/advisories/GHSA-786w-p5pm-cvgh
github.com

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