CVE-2026-17539

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

Score 5.9 from GitHub Security Advisory published 2026-09-03. A secondary CVSS source baseline 5.9; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 5.9Exploit: None knownExposed services: Not assessed

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

RTU500 has a vulnerability, where high-load scenarios, such as sending GI requests at short intervals, may cause a NULL pointer dereference in the last entry of the enhanced message queue. This can cause a BCI_IEC104 fatal write error, resulting in connection interruption and restart, and ultimately a denial of service for bidirectional IEC 60870-5-104 communication.

CVSS v3
5.9
EG Score
5.9MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100CISA 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
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.
EPSS PROB
0.3%
EPSS %ILE
17th
KEV
Not listed

CISA SSVCTrack at every mission impact level.

No fix is confirmed yet. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines, and watch the vendor's advisory for the fix.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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

September 3, 2026

Last Modified

September 3, 2026

Advisory Details (1)

Auto-updated Sep 3, 2026
No patch confirmed yet.
generic

Hitachi Energy Publisher

https://publisher.hitachienergy.com/preview?DocumentID=8DBD000259&LanguageCode=en&DocumentPartId=&Action=Launch

Vendor Advisories for CVE-2026-17539(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 19× in last 7d / 74× 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. 2026-10-04 02:46 UTCEG score recompute
  2. 2026-10-04 02:46 UTCGHSA enrichment
  3. 2026-10-03 14:25 UTCEPSS rescore
  4. 2026-10-03 03:12 UTCEG score recompute
  5. 2026-10-03 03:12 UTCGHSA enrichment
  6. 2026-10-02 03:38 UTCEG score recompute
  7. 2026-10-02 03:38 UTCGHSA enrichment
  8. 2026-10-01 19:49 UTCEPSS rescore
  9. 2026-10-01 03:50 UTCEG score recompute
  10. 2026-10-01 03:50 UTCGHSA enrichment
  11. 2026-09-30 15:02 UTCEPSS rescore
  12. 2026-09-30 04:16 UTCEG score recompute
  13. 2026-09-30 04:16 UTCGHSA enrichment
  14. 2026-09-29 15:20 UTCEPSS rescore
  15. 2026-09-29 04:42 UTCEG score recompute
  16. 2026-09-29 04:42 UTCGHSA enrichment
  17. 2026-09-28 13:51 UTCEPSS rescore
  18. 2026-09-28 05:09 UTCEG score recompute
  19. 2026-09-28 05:09 UTCGHSA enrichment
  20. 2026-09-27 13:47 UTCEPSS rescore
  21. 2026-09-27 05:35 UTCEG score recompute
  22. 2026-09-27 05:35 UTCGHSA enrichment
  23. 2026-09-26 15:58 UTCEPSS rescore
  24. 2026-09-26 04:49 UTCEG score recompute
  25. 2026-09-26 04:49 UTCGHSA enrichment
Show 56 more
  1. 2026-09-24 19:23 UTCEG score recompute
  2. 2026-09-24 19:23 UTCGHSA enrichment
  3. 2026-09-23 19:48 UTCEG score recompute
  4. 2026-09-23 19:48 UTCGHSA enrichment
  5. 2026-09-22 19:40 UTCEG score recompute
  6. 2026-09-22 19:40 UTCGHSA enrichment
  7. 2026-09-21 20:06 UTCGHSA enrichment
  8. 2026-09-20 20:32 UTCEG score recompute
  9. 2026-09-20 20:32 UTCGHSA enrichment
  10. 2026-09-19 20:58 UTCEG score recompute
  11. 2026-09-19 20:58 UTCGHSA enrichment
  12. 2026-09-18 21:24 UTCEG score recompute
  13. 2026-09-18 21:24 UTCGHSA enrichment
  14. 2026-09-18 19:27 UTCEPSS rescore
  15. 2026-09-17 20:55 UTCEG score recompute
  16. 2026-09-17 20:55 UTCGHSA enrichment
  17. 2026-09-16 21:21 UTCEG score recompute
  18. 2026-09-16 21:21 UTCGHSA enrichment
  19. 2026-09-16 14:07 UTCEPSS rescore
  20. 2026-09-16 05:14 UTCEPSS rescore
  21. 2026-09-15 21:31 UTCEG score recompute
  22. 2026-09-15 21:31 UTCGHSA enrichment
  23. 2026-09-14 21:57 UTCGHSA enrichment
  24. 2026-09-13 22:23 UTCEG score recompute
  25. 2026-09-13 22:23 UTCGHSA enrichment
  26. 2026-09-13 16:46 UTCEPSS rescore
  27. 2026-09-12 22:50 UTCEG score recompute
  28. 2026-09-12 22:50 UTCGHSA enrichment
  29. 2026-09-12 15:00 UTCEPSS rescore
  30. 2026-09-11 23:16 UTCEG score recompute
  31. 2026-09-11 23:16 UTCGHSA enrichment
  32. 2026-09-11 14:52 UTCEPSS rescore
  33. 2026-09-11 09:36 UTCEPSS rescore
  34. 2026-09-10 23:04 UTCEG score recompute
  35. 2026-09-10 23:04 UTCGHSA enrichment
  36. 2026-09-10 09:34 UTCEPSS rescore
  37. 2026-09-09 23:30 UTCGHSA enrichment
  38. 2026-09-08 23:10 UTCEG score recompute
  39. 2026-09-08 23:10 UTCGHSA enrichment
  40. 2026-09-08 22:00 UTCEPSS rescore
  41. 2026-09-07 16:01 UTCEPSS rescore
  42. 2026-09-07 15:12 UTCGHSA enrichment
  43. 2026-09-06 15:39 UTCEG score recompute
  44. 2026-09-06 15:39 UTCGHSA enrichment
  45. 2026-09-06 13:47 UTCEPSS rescore
  46. 2026-09-05 16:05 UTCEG score recompute
  47. 2026-09-05 16:05 UTCGHSA enrichment
  48. 2026-09-04 16:31 UTCEG score recompute
  49. 2026-09-04 16:31 UTCGHSA enrichment
  50. 2026-09-04 05:06 UTCEPSS rescore
  51. 2026-09-03 16:54 UTCEG score recompute
  52. 2026-09-03 16:54 UTCGHSA enrichment
  53. 2026-09-03 13:15 UTCEG score recompute
  54. 2026-09-03 13:02 UTCEG score recompute
  55. 2026-09-03 08:09 UTCEG score recompute
  56. 2026-09-03 08:09 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-17539?
CVE-2026-17539 is a medium vulnerability published on September 3, 2026. RTU500 has a vulnerability, where high-load scenarios, such as sending GI requests at short intervals, may cause a NULL pointer dereference in the last entry of the enhanced message queue. This can cause a BCI_IEC104 fatal write error, resulting in connection interruption and restart, and…
When was CVE-2026-17539 disclosed?
CVE-2026-17539 was first published on September 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-17539 actively exploited?
CVE-2026-17539 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (17th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-17539?
CVE-2026-17539 has a CVSS base score of 5.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-17539?
No fix for CVE-2026-17539 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. The vendor advisories EchelonGraph has for CVE-2026-17539 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-17539

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