CVE-2026-55584

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 2.4%, top 17% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
65(Track)
EG Risk 65/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
83%
KEV
Not listed

Published

August 28, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Aug 28, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github.
github Patch Available🟡 PoC Available

IP allowlist (PSI_ALLOWED) bypass via spoofed X-Forwarded-For / Client-IP headers · Advisory · phpsysinfo/phpsysinfo · GitHub

https://github.com/phpsysinfo/phpsysinfo/security/advisories/GHSA-786w-p5pm-cvgh
github_release Patch Available

phpSysInfo 3.4.6

Patch available: phpsysinfo/phpsysinfo v3.4.6

https://github.com/phpsysinfo/phpsysinfo/releases/tag/v3.4.6
github_commit Patch Available

commit 019fa2d7e568 (phpsysinfo/phpsysinfo)

Patch available: phpsysinfo/phpsysinfo v3.4.6 (contains commit 019fa2d7e568)

https://github.com/phpsysinfo/phpsysinfo/commit/019fa2d7e568ea11461adb4bd33da5dc87c4b9ab

Vendor Advisories for CVE-2026-55584(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
phpsysinfo3.4.2-3 ... 3.4.4-2 (6 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
phpsysinfo3.4.4-1, 3.4.4-2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
phpsysinfo3.4.4-1, 3.4.4-2——
Packagist(1)
PackageVulnerable rangeFixed inDependents
phpsysinfo/phpsysinfov3.1.13 ... v3.4.5 (27 versions)3.4.6—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 13× in last 7d / 40× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 18:43 UTCEG score recompute
  2. 2026-09-19 05:33 UTCEG score recompute
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 03:12 UTCEG score recompute
  5. 2026-09-17 19:31 UTCEPSS rescore
  6. 2026-09-17 00:52 UTCEG score recompute
  7. 2026-09-16 14:08 UTCEPSS rescore
  8. 2026-09-16 11:41 UTCEG score recompute
  9. 2026-09-16 05:15 UTCEPSS rescore
  10. 2026-09-15 09:21 UTCEG score recompute
  11. 2026-09-15 03:11 UTCEPSS rescore
  12. 2026-09-13 17:51 UTCEG score recompute
  13. 2026-09-13 16:47 UTCEPSS rescore
  14. 2026-09-12 15:29 UTCEG score recompute
  15. 2026-09-12 02:19 UTCEG score recompute
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-11 13:08 UTCEG score recompute
  18. 2026-09-10 10:21 UTCEG score recompute
  19. 2026-09-10 09:35 UTCEPSS rescore
  20. 2026-09-09 01:30 UTCEG score recompute
  21. 2026-09-08 22:01 UTCEPSS rescore
  22. 2026-09-06 20:45 UTCEG score recompute
  23. 2026-09-06 13:47 UTCEPSS rescore
  24. 2026-09-05 18:24 UTCEG score recompute
  25. 2026-09-04 16:03 UTCEG score recompute
Show 15 more
  1. 2026-09-04 05:06 UTCEPSS rescore
  2. 2026-09-03 00:25 UTCEG score recompute
  3. 2026-09-02 14:12 UTCEPSS rescore
  4. 2026-09-01 21:51 UTCEG score recompute
  5. 2026-09-01 13:54 UTCEPSS rescore
  6. 2026-09-01 08:41 UTCEG score recompute
  7. 2026-09-01 04:40 UTCEPSS rescore
  8. 2026-08-31 19:31 UTCEG score recompute
  9. 2026-08-31 18:57 UTCEG score recompute
  10. 2026-08-31 01:08 UTCEG score recompute
  11. 2026-08-30 19:17 UTCEPSS rescore
  12. 2026-08-30 11:58 UTCEG score recompute
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 20:24 UTCEG score recompute
  15. 2026-08-28 19:10 UTCEG score recompute

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-52648
    First seen Aug 17, 2026

    phpSysInfo 3.4.5 - IP Allowlist Bypass

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55584?
CVE-2026-55584 is a high vulnerability published on August 28, 2026. phpSysInfo is a customizable PHP script that displays system information. Prior to 3.4.6, the PSIALLOWED access-control check in readconfig.php trusts attacker-controlled X-Forwarded-For and Client-IP HTTP headers before REMOTE_ADDR. A remote unauthenticated attacker can supply an allowed address…
When was CVE-2026-55584 disclosed?
CVE-2026-55584 was first published in the National Vulnerability Database on August 28, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55584 actively exploited?
CVE-2026-55584 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 16.6% of all scored CVEs.
What is the CVSS score of CVE-2026-55584?
CVE-2026-55584 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-55584?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55584, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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