CVE-2020-12256

CRITICALNVD 5.49.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because EPSS predicts 96% probability of exploitation within the next 30 days (99th percentile of EPSS-scored CVEs). NVD baseline CVSS 5.4 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, nvd
Elevated
9.0EG
EchelonGraph verdictMitigate this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 96%
CISA-KEV: Not listedEPSS PROB: 96%CVSS: 5.4Exploit: Elevated riskExposed services: Not assessed

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

rConfig 3.9.4 is vulnerable to reflected XSS. The devicemgmnt.php file improperly validates user input. An attacker can exploit this by crafting arbitrary JavaScript in the deviceId GET parameter to devicemgmnt.php.

CVSS v3
5.4
EG Score
9.0CRITICALhigh confidence
EG Risk
83
EG Risk 83/100CISA SSVC

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
Severity90% × 45%
Exploitation96% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.
EPSS PROB
96%
EPSS %ILE
99th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines at low or medium mission impact and sooner than that at high, and watch the vendor's advisory for the fix.

Exploitation public PoC (EG-KEV: elevated) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

May 18, 2020

Last Modified

November 21, 2024

References (2)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 1× in last 7d / 8× 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. 2026-09-30 10:33 UTCEG score recompute
  2. 2026-09-26 15:54 UTCEPSS rescore
  3. 2026-09-24 13:59 UTCEPSS rescore
  4. 2026-09-22 14:43 UTCEPSS rescore
  5. 2026-09-21 20:28 UTCEPSS rescore
  6. 2026-09-11 09:32 UTCEPSS rescore
  7. 2026-09-07 15:57 UTCEPSS rescore
  8. 2026-09-06 13:44 UTCEPSS rescore
  9. 2026-09-05 15:24 UTCEPSS rescore
  10. 2026-09-01 03:32 UTCEPSS rescore
  11. 2026-08-30 19:14 UTCEPSS rescore
  12. 2026-08-30 01:18 UTCEPSS rescore
  13. 2026-08-28 21:37 UTCEPSS rescore
  14. 2026-08-27 14:21 UTCEPSS rescore
  15. 2026-08-16 14:52 UTCEPSS rescore
  16. 2026-08-12 13:47 UTCEPSS rescore
  17. 2026-08-08 16:33 UTCEPSS rescore
  18. 2026-08-06 13:43 UTCEPSS rescore
  19. 2026-08-04 10:34 UTCEPSS rescore
  20. 2026-08-02 02:23 UTCEPSS rescore
  21. 2026-07-25 14:14 UTCEPSS rescore
  22. 2026-07-23 01:48 UTCEG score recompute
  23. 2026-07-22 21:29 UTCEG score recompute▲ 3.60
  24. 2026-07-22 21:29 UTCGHSA enrichment
  25. 2026-07-22 14:05 UTCEPSS rescore
Show 44 more
  1. 2026-07-11 08:24 UTCEPSS rescore
  2. 2026-07-09 19:06 UTCEPSS rescore
  3. 2026-06-24 14:03 UTCEPSS rescore
  4. 2026-06-24 14:03 UTCEPSS rescore
  5. 2026-06-23 21:31 UTCEPSS rescore
  6. 2026-06-23 21:31 UTCEPSS rescore
  7. 2026-06-18 17:50 UTCEPSS rescore
  8. 2026-06-18 17:50 UTCEPSS rescore
  9. 2026-06-17 17:50 UTCEPSS rescore
  10. 2026-06-17 17:50 UTCEPSS rescore
  11. 2026-06-15 17:46 UTCEPSS rescore
  12. 2026-06-12 23:09 UTCEPSS rescore
  13. 2026-06-11 13:58 UTCEPSS rescore
  14. 2026-06-10 22:16 UTCEPSS rescore
  15. 2026-06-10 22:16 UTCEPSS rescore
  16. 2026-06-10 13:20 UTCEPSS rescore
  17. 2026-06-08 14:15 UTCEPSS rescore
  18. 2026-06-08 14:15 UTCEPSS rescore
  19. 2026-06-07 15:23 UTCEPSS rescore
  20. 2026-06-07 15:23 UTCEPSS rescore
  21. 2026-06-06 13:45 UTCEPSS rescore
  22. 2026-06-06 13:45 UTCEPSS rescore
  23. 2026-06-06 13:45 UTCEPSS rescore
  24. 2026-06-05 22:45 UTCEPSS rescore
  25. 2026-06-05 22:45 UTCEPSS rescore
  26. 2026-06-05 06:08 UTCEPSS rescore
  27. 2026-06-04 13:10 UTCEPSS rescore
  28. 2026-06-04 13:10 UTCEPSS rescore
  29. 2026-06-02 20:11 UTCEPSS rescore
  30. 2026-06-02 20:11 UTCEPSS rescore
  31. 2026-06-01 13:50 UTCEPSS rescore
  32. 2026-05-31 22:29 UTCEPSS rescore
  33. 2026-05-31 22:29 UTCEPSS rescore
  34. 2026-05-31 00:15 UTCEPSS rescore
  35. 2026-05-31 00:14 UTCEPSS rescore
  36. 2026-05-29 13:42 UTCEPSS rescore
  37. 2026-05-29 13:42 UTCEPSS rescore
  38. 2026-05-28 13:43 UTCEPSS rescore
  39. 2026-05-28 13:43 UTCEPSS rescore
  40. 2026-05-27 13:39 UTCEPSS rescore
  41. 2026-05-27 03:31 UTCEG score recompute
  42. 2026-05-27 03:31 UTCGHSA enrichment
  43. 2026-05-26 13:42 UTCEPSS rescore
  44. 2026-05-26 13:42 UTCEPSS rescore

Publicly available exploits

(1 reference)

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

  • Nucleihttp/cves/2020/CVE-2020-12256.yaml
    First seen Jan 1, 2020

    rConfig 3.9.4 - Cross-Site Scripting

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2020-12256?
CVE-2020-12256 is a critical vulnerability published on May 18, 2020. rConfig 3.9.4 is vulnerable to reflected XSS. The devicemgmnt.php file improperly validates user input. An attacker can exploit this by crafting arbitrary JavaScript in the deviceId GET parameter to devicemgmnt.php.
When was CVE-2020-12256 disclosed?
CVE-2020-12256 was first published on May 18, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-12256 actively exploited?
CVE-2020-12256 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 96% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2020-12256?
CVE-2020-12256 has a CVSS v3 base score of 5.4 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0 (CRITICAL).
How do I remediate CVE-2020-12256?
No fix for CVE-2020-12256 is confirmed yet. Until one is published, restrict network exposure of the affected system or apply the vendor's mitigation — for example, keep it off the internet or limit it to trusted networks — and watch the vendor's advisory for the fix.

Dependency Blast Radius

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