CVE-2021-22681

CRITICALNVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score elevated to 9.8 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-03-05), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 9.8 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
9.8
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 51%CVSS: 9.8Exploit: NoneExposed: 0

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

Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800. Rockwell Automation Studio 5000 Logix Designer Versions 21 and later and RSLogix 5000: Versions 16 through 20 are vulnerable because an unauthenticated attacker could bypass this verification mechanism and authenticate with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730, 1794-L34; Compact GuardLogix 5370, 5380; GuardLogix 5570, 5580; SoftLogix 5800.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
99(Act)
EG Risk 99/100SSVC: Act

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
Severity98% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Fix now — active exploitation, automatable, high impact.
EPSS
98.8%
KEV
⚠ Exploited

Published

March 3, 2021

Last Modified

March 6, 2026

Advisory Details (2)

Auto-updated May 26, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: 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-2021-22681
cisa Patch Available

Rockwell Automation Logix Controllers (Update A) | CISA

https://us-cert.cisa.gov/ics/advisories/icsa-21-056-03

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 49× in last 7d / 239× 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 469 total refreshes for this CVE.

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

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Frequently asked(6)

What is CVE-2021-22681?
CVE-2021-22681 is a critical vulnerability published on March 3, 2021. Rockwell Automation Studio 5000 Logix Designer Versions 21 and later, and RSLogix 5000 Versions 16 through 20 use a key to verify Logix controllers are communicating with Rockwell Automation CompactLogix 1768, 1769, 5370, 5380, 5480: ControlLogix 5550, 5560, 5570, 5580; DriveLogix 5560, 5730,…
When was CVE-2021-22681 disclosed?
CVE-2021-22681 was first published in the National Vulnerability Database on March 3, 2021, with the most recent update on March 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-22681 actively exploited?
Yes. CISA added CVE-2021-22681 to the Known Exploited Vulnerabilities catalog on March 5, 2026, affecting Rockwell Multiple Products. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-22681?
CVE-2021-22681 has a CVSS v3 base score of 9.8 (NVD).
Which products are affected by CVE-2021-22681?
CVE-2021-22681 affects Rockwell Multiple Products. 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-2021-22681?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-22681, 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.

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