CVE-2026-51221

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-30. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

A buffer overflow in the Get_Attribute_List function of EIPStackGroup OpENer commit 76b95c allows attackers to cause a Denial of Service (DoS) via supplying a crafted Common Packet Format (CPF) packet.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

June 29, 2026

Last Modified

June 30, 2026

Advisory Details (2)

Auto-updated Jun 30, 2026
No patch confirmed yet.
generic

Malformed CPF and Get_Attribute_List request leads to pointer corruption and `denial of service` in OpENer · Issue #567 · EIPStackGroup/OpENer · GitHub

https://github.com/EIPStackGroup/OpENer/issues/567
generic

GitHub - EIPStackGroup/OpENer: OpENer is an EtherNet/IP stack for I/O adapter devices. It supports multiple I/O and explicit connections and includes objects and services for making EtherNet/IP-compliant products as defined in the ODVA specification. · GitHub

https://github.com/EIPStackGroup/OpENer

Vendor Advisories for CVE-2026-51221(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 7× in last 7d / 66× 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 207 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-51221?
CVE-2026-51221 is a high vulnerability published on June 29, 2026. A buffer overflow in the GetAttributeList function of EIPStackGroup OpENer commit 76b95c allows attackers to cause a Denial of Service (DoS) via supplying a crafted Common Packet Format (CPF) packet.
When was CVE-2026-51221 disclosed?
CVE-2026-51221 was first published in the National Vulnerability Database on June 29, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-51221 actively exploited?
CVE-2026-51221 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 59.5% of all scored CVEs.
What is the CVSS score of CVE-2026-51221?
CVE-2026-51221 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-51221?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-51221, 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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