CVE-2026-55584 json
phpSysInfo: IP allowlist (PSI_ALLOWED) bypass via spoofed X-Forwarded-For / Client-IP headers
published 2026-08-28 2 mo ago modified 2026-09-09 1 mo ago also EUVD-2026-67862 , GHSA-786w-p5pm-cvgh
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.9%
- EPSS 1.9% chance of exploitation in 30 days, percentile 79%
- public exploits
- 1
- Exploit-DB
Summary
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.
Patch / fix
- packagist phpsysinfo/phpsysinfo 3.4.6
- phpsysinfo phpsysinfo 3.4.6
Timeline
- First public exploit (EDB-52648)
- Published
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 2 mo ago
Exploit prediction
1.91% chance of exploitation in the next 30 days, higher than 79% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- EDB-52648 phpSysInfo 3.4.5 - IP Allowlist Bypass remote, 2026-08-17
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | phpsysinfo/phpsysinfo | <3.4.6 |
3.4.6 |
Affected products
- phpsysinfo phpsysinfo
Classification
- Weakness
-
- CWE-290 Authentication Bypass by Spoofing
References
Sources
- CVE List CVE-2026-55584
- GitHub Advisory GHSA-786w-p5pm-cvgh
- NVD CVE-2026-55584
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.