CVE-2026-9621

CRITICALPre-NVD 9.29.2—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.2 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 76% 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
Trending — 3 sources updated this week
9.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.2Exploit: None knownExposed: 0

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

A denial-of-service security issue exists within RSLinx® Classic. The security issue stems from improper handling of a malformed packet. A crafted CIP packet can cause the RSLinx® Classic service to crash, requiring a restart of the service to recover

CVSS v3
9.2
EG Score
9.2(medium)
EG Risk
57(Track)
EG Risk 57/100SSVC: 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
Severity92% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 1, 2026

Advisory Details (1)

Auto-updated Sep 15, 2026
No patch confirmed yet.
generic

SD1794 | Security Advisory | Rockwell Automation | US

https://www.rockwellautomation.com/en-us/trust-center/security-advisories/advisory.SD1794.html

Vendor Advisories for CVE-2026-9621(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 55× in last 7d / 160× 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 160 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-9621?
CVE-2026-9621 is a critical vulnerability published on September 1, 2026. A denial-of-service security issue exists within RSLinx® Classic. The security issue stems from improper handling of a malformed packet. A crafted CIP packet can cause the RSLinx® Classic service to crash, requiring a restart of the service to recover
When was CVE-2026-9621 disclosed?
CVE-2026-9621 was first published in the National Vulnerability Database on September 1, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9621 actively exploited?
CVE-2026-9621 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 75.8% of all scored CVEs.
What is the CVSS score of CVE-2026-9621?
CVE-2026-9621 has a CVSS v3 base score of 9.2 (NVD).
How do I remediate CVE-2026-9621?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9621, 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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