CVE-2021-26828

CRITICALNVD 8.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2025-12-03), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 8.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 4 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 39%CVSS: 8.8Exploit: cisa kev · ssvc active · epss top5pct · public exploitExposed: 0

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

OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows remote authenticated users to upload and execute arbitrary JSP files via view_edit.shtm.

CVSS v3
8.8
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

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%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
39%
EPSS %ILE
99%
KEV
⚠ Exploited

Published

June 11, 2021

Last Modified

December 4, 2025

Advisory Details (4)

Auto-updated Jun 2, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: github_pr, cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26828
github_pr Patch Available

#2173 Fixed import project CVE-2021-26828 - added filtering, for grag…

Patch available: SCADA-LTS/Scada-LTS v2.7.1 (PR #2174 merged 2022-04-27)

https://github.com/SCADA-LTS/Scada-LTS/pull/2174
generic
https://youtu.be/k1teIStQr1A
generic

[REPORT] Falhas de segurança em versões do ScadaBR - #4 de h3v0x - ScadaBR - Geral - ScadaBR

http://forum.scadabr.com.br/t/report-falhas-de-seguranca-em-versoes-do-scadabr/3615/4

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 60× in last 7d / 252× 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.

Showing the most recent 100 of 913 total refreshes for this CVE.

  1. 2026-09-20 15:33 UTCGHSA enrichment
  2. 2026-09-20 11:38 UTCGHSA enrichment
  3. 2026-09-20 07:42 UTCGHSA enrichment
  4. 2026-09-20 03:44 UTCGHSA enrichment
  5. 2026-09-19 23:50 UTCGHSA enrichment
  6. 2026-09-19 19:56 UTCGHSA enrichment
  7. 2026-09-19 16:02 UTCEG score recompute
  8. 2026-09-19 16:02 UTCGHSA enrichment
  9. 2026-09-19 15:37 UTCEPSS rescore
  10. 2026-09-19 12:07 UTCGHSA enrichment
  11. 2026-09-19 08:13 UTCGHSA enrichment
  12. 2026-09-19 04:18 UTCGHSA enrichment
  13. 2026-09-19 00:24 UTCGHSA enrichment
  14. 2026-09-18 20:30 UTCEG score recompute
  15. 2026-09-18 20:30 UTCGHSA enrichment
  16. 2026-09-18 19:23 UTCEPSS rescore
  17. 2026-09-18 19:20 UTCCISA KEV update
  18. 2026-09-18 16:36 UTCGHSA enrichment
  19. 2026-09-18 14:15 UTCCISA KEV update
  20. 2026-09-18 12:42 UTCGHSA enrichment
  21. 2026-09-18 08:48 UTCGHSA enrichment
  22. 2026-09-18 04:54 UTCGHSA enrichment
  23. 2026-09-18 01:00 UTCGHSA enrichment
  24. 2026-09-17 21:05 UTCEG score recompute
  25. 2026-09-17 21:05 UTCGHSA enrichment
Show 75 more
  1. 2026-09-17 19:23 UTCEPSS rescore
  2. 2026-09-17 19:23 UTCEPSS rescore
  3. 2026-09-17 17:11 UTCGHSA enrichment
  4. 2026-09-17 13:10 UTCGHSA enrichment
  5. 2026-09-17 09:16 UTCGHSA enrichment
  6. 2026-09-17 05:22 UTCGHSA enrichment
  7. 2026-09-17 01:28 UTCGHSA enrichment
  8. 2026-09-16 21:34 UTCGHSA enrichment
  9. 2026-09-16 17:40 UTCEG score recompute
  10. 2026-09-16 17:39 UTCGHSA enrichment
  11. 2026-09-16 14:10 UTCCISA KEV update
  12. 2026-09-16 14:05 UTCEPSS rescore
  13. 2026-09-16 13:42 UTCGHSA enrichment
  14. 2026-09-16 09:44 UTCGHSA enrichment
  15. 2026-09-16 05:50 UTCEG score recompute
  16. 2026-09-16 05:50 UTCGHSA enrichment
  17. 2026-09-16 01:56 UTCGHSA enrichment
  18. 2026-09-15 22:02 UTCGHSA enrichment
  19. 2026-09-15 18:07 UTCGHSA enrichment
  20. 2026-09-15 14:13 UTCGHSA enrichment
  21. 2026-09-15 10:18 UTCGHSA enrichment
  22. 2026-09-15 06:24 UTCEG score recompute
  23. 2026-09-15 06:23 UTCGHSA enrichment
  24. 2026-09-15 03:06 UTCEPSS rescore
  25. 2026-09-15 03:06 UTCEPSS rescore
  26. 2026-09-15 02:29 UTCGHSA enrichment
  27. 2026-09-14 22:32 UTCGHSA enrichment
  28. 2026-09-14 19:24 UTCCISA KEV update
  29. 2026-09-14 18:38 UTCGHSA enrichment
  30. 2026-09-14 14:44 UTCGHSA enrichment
  31. 2026-09-14 10:49 UTCGHSA enrichment
  32. 2026-09-14 06:55 UTCGHSA enrichment
  33. 2026-09-14 03:01 UTCGHSA enrichment
  34. 2026-09-13 23:07 UTCGHSA enrichment
  35. 2026-09-13 19:13 UTCGHSA enrichment
  36. 2026-09-13 15:19 UTCGHSA enrichment
  37. 2026-09-13 11:25 UTCGHSA enrichment
  38. 2026-09-13 07:31 UTCGHSA enrichment
  39. 2026-09-13 03:36 UTCGHSA enrichment
  40. 2026-09-12 23:42 UTCGHSA enrichment
  41. 2026-09-12 19:48 UTCGHSA enrichment
  42. 2026-09-12 15:54 UTCEG score recompute
  43. 2026-09-12 15:54 UTCGHSA enrichment
  44. 2026-09-12 14:57 UTCEPSS rescore
  45. 2026-09-12 12:00 UTCGHSA enrichment
  46. 2026-09-12 08:06 UTCGHSA enrichment
  47. 2026-09-12 04:12 UTCGHSA enrichment
  48. 2026-09-12 00:18 UTCGHSA enrichment
  49. 2026-09-11 20:24 UTCGHSA enrichment
  50. 2026-09-11 18:49 UTCCISA KEV update
  51. 2026-09-11 16:30 UTCEG score recompute
  52. 2026-09-11 16:30 UTCGHSA enrichment
  53. 2026-09-11 14:49 UTCEPSS rescore
  54. 2026-09-11 12:35 UTCEG score recompute
  55. 2026-09-11 12:35 UTCGHSA enrichment
  56. 2026-09-11 09:33 UTCEPSS rescore
  57. 2026-09-11 08:37 UTCGHSA enrichment
  58. 2026-09-11 04:43 UTCGHSA enrichment
  59. 2026-09-11 00:49 UTCGHSA enrichment
  60. 2026-09-10 20:55 UTCGHSA enrichment
  61. 2026-09-10 19:28 UTCCISA KEV update
  62. 2026-09-10 17:00 UTCGHSA enrichment
  63. 2026-09-10 13:06 UTCEG score recompute
  64. 2026-09-10 13:06 UTCGHSA enrichment
  65. 2026-09-10 09:12 UTCGHSA enrichment
  66. 2026-09-10 05:18 UTCGHSA enrichment
  67. 2026-09-10 01:23 UTCGHSA enrichment
  68. 2026-09-09 21:29 UTCGHSA enrichment
  69. 2026-09-09 19:08 UTCCISA KEV update
  70. 2026-09-09 17:35 UTCGHSA enrichment
  71. 2026-09-09 13:40 UTCGHSA enrichment
  72. 2026-09-09 09:46 UTCGHSA enrichment
  73. 2026-09-09 05:52 UTCGHSA enrichment
  74. 2026-09-09 01:58 UTCGHSA enrichment
  75. 2026-09-08 22:03 UTCGHSA enrichment

Publicly available exploits

(2 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCridpath/CVE-2021-26828-Ultimate
    First seen May 30, 2025

    ScadaFlare Authenticated RCE Exploit Framework for ScadaBR (CVE-2021-26828) OpenPLC ScadaBR

    Open source ↗
  • GitHub PoChev0x/CVE-2021-26828_ScadaBR_RCE
    First seen Mar 31, 2021
    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-26828?
CVE-2021-26828 is a critical vulnerability published on June 11, 2021. OpenPLC ScadaBR through 0.9.1 on Linux and through 1.12.4 on Windows allows remote authenticated users to upload and execute arbitrary JSP files via view_edit.shtm.
When was CVE-2021-26828 disclosed?
CVE-2021-26828 was first published in the National Vulnerability Database on June 11, 2021, with the most recent update on December 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-26828 actively exploited?
Yes. CISA added CVE-2021-26828 to the Known Exploited Vulnerabilities catalog on December 3, 2025, affecting OpenPLC ScadaBR. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-26828?
CVE-2021-26828 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2021-26828?
CVE-2021-26828 affects OpenPLC ScadaBR. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2021-26828?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-26828, 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

Explore the affected products and dependency analysis for CVE-2021-26828

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