CVE-2026-66369

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-31. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

The GOOSE parser contains an off-by-one boundary-handling flaw that can be triggered by a single unauthenticated Layer-2 multicast frame on the process bus. When specific GOOSE message fields are processed, the parser advances its internal buffer position incorrectly, resulting in a heap out-of-bounds read. On affected platforms, this condition reliably terminates the subscriber process and causes a denial-of-service.

CVSS v3
6.5
EG Score
6.5(high)
EG Risk
29(Track)
EG Risk 29/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

July 30, 2026

Last Modified

July 31, 2026

Advisory Details (2)

Auto-updated Jul 30, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: cisa.
cisa Patch Available🔴 Active Exploitation

MZ Automation GmbH libiec61850 | CISA

MZ Automation GmbH libiec61850 | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/news-events/ics-advisories/icsa-26-211-10
generic

CSAF/csaf_files/OT/white/2026/icsa-26-211-10.json at develop · cisagov/CSAF · GitHub

https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-211-10.json

Vendor Advisories for CVE-2026-66369(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 20× in last 7d / 64× 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. 2026-08-20 22:56 UTCEPSS rescore
  2. 2026-08-20 15:08 UTCEG score recompute
  3. 2026-08-20 15:08 UTCGHSA enrichment
  4. 2026-08-19 17:04 UTCEPSS rescore
  5. 2026-08-19 14:03 UTCEG score recompute
  6. 2026-08-19 14:03 UTCGHSA enrichment
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-18 12:54 UTCEG score recompute
  9. 2026-08-18 12:53 UTCGHSA enrichment
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-17 11:55 UTCEG score recompute
  12. 2026-08-17 11:55 UTCGHSA enrichment
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 10:57 UTCEG score recompute
  15. 2026-08-16 10:57 UTCGHSA enrichment
  16. 2026-08-15 10:00 UTCEG score recompute
  17. 2026-08-15 10:00 UTCGHSA enrichment
  18. 2026-08-15 01:30 UTCEPSS rescore
  19. 2026-08-14 09:02 UTCEG score recompute
  20. 2026-08-14 09:02 UTCGHSA enrichment
  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-13 08:04 UTCEG score recompute
  23. 2026-08-13 08:04 UTCGHSA enrichment
  24. 2026-08-12 13:51 UTCEPSS rescore
  25. 2026-08-12 07:06 UTCEG score recompute
Show 39 more
  1. 2026-08-12 07:06 UTCGHSA enrichment
  2. 2026-08-11 06:08 UTCEG score recompute
  3. 2026-08-11 06:08 UTCGHSA enrichment
  4. 2026-08-11 00:00 UTCEPSS rescore
  5. 2026-08-10 05:11 UTCEG score recompute
  6. 2026-08-10 05:11 UTCGHSA enrichment
  7. 2026-08-09 13:47 UTCEPSS rescore
  8. 2026-08-09 04:13 UTCEG score recompute
  9. 2026-08-09 04:13 UTCGHSA enrichment
  10. 2026-08-08 16:37 UTCEPSS rescore
  11. 2026-08-08 03:16 UTCEG score recompute
  12. 2026-08-08 03:16 UTCGHSA enrichment
  13. 2026-08-07 02:18 UTCEG score recompute
  14. 2026-08-07 02:18 UTCGHSA enrichment
  15. 2026-08-06 13:47 UTCEPSS rescore
  16. 2026-08-06 01:20 UTCEG score recompute
  17. 2026-08-06 01:20 UTCGHSA enrichment
  18. 2026-08-05 19:17 UTCEPSS rescore
  19. 2026-08-05 19:17 UTCEPSS rescore
  20. 2026-08-05 00:23 UTCEG score recompute
  21. 2026-08-05 00:23 UTCGHSA enrichment
  22. 2026-08-04 15:10 UTCEPSS rescore
  23. 2026-08-04 10:39 UTCEPSS rescore
  24. 2026-08-03 23:17 UTCEG score recompute
  25. 2026-08-03 23:17 UTCGHSA enrichment
  26. 2026-08-03 10:36 UTCEPSS rescore
  27. 2026-08-02 22:20 UTCEG score recompute
  28. 2026-08-02 22:20 UTCGHSA enrichment
  29. 2026-08-02 02:27 UTCEPSS rescore
  30. 2026-08-01 21:22 UTCEG score recompute
  31. 2026-08-01 21:22 UTCGHSA enrichment
  32. 2026-08-01 04:16 UTCEPSS rescore
  33. 2026-07-31 20:24 UTCEG score recompute
  34. 2026-07-31 20:24 UTCGHSA enrichment
  35. 2026-07-31 19:49 UTCEG score recompute
  36. 2026-07-31 19:49 UTCGHSA enrichment
  37. 2026-07-30 23:20 UTCEG score recompute
  38. 2026-07-30 23:12 UTCEG score recompute
  39. 2026-07-30 23:10 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-66369?
CVE-2026-66369 is a medium vulnerability published on July 30, 2026. The GOOSE parser contains an off-by-one boundary-handling flaw that can be triggered by a single unauthenticated Layer-2 multicast frame on the process bus. When specific GOOSE message fields are processed, the parser advances its internal buffer position incorrectly, resulting in a heap…
When was CVE-2026-66369 disclosed?
CVE-2026-66369 was first published in the National Vulnerability Database on July 30, 2026, with the most recent update on July 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-66369 actively exploited?
CVE-2026-66369 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 92.8% of all scored CVEs.
What is the CVSS score of CVE-2026-66369?
CVE-2026-66369 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-66369?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-66369, 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-2026-66369

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