CVE-2026-51221

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH 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 — 4 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 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(high)
EPSS
27.1%
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 28× in last 7d / 31× 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. 2026-07-06 22:27 UTCEG score recompute
  2. 2026-07-06 22:27 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 11:32 UTCEG score recompute
  6. 2026-07-06 11:32 UTCGHSA enrichment
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-06 00:37 UTCEG score recompute
  9. 2026-07-06 00:37 UTCGHSA enrichment
  10. 2026-07-05 13:42 UTCEG score recompute
  11. 2026-07-05 13:42 UTCGHSA enrichment
  12. 2026-07-05 02:47 UTCEG score recompute
  13. 2026-07-05 02:47 UTCGHSA enrichment
  14. 2026-07-05 02:30 UTCEPSS rescore
  15. 2026-07-04 15:51 UTCEG score recompute
  16. 2026-07-04 15:51 UTCGHSA enrichment
  17. 2026-07-04 06:31 UTCEPSS rescore
  18. 2026-07-04 04:56 UTCEG score recompute
  19. 2026-07-04 04:56 UTCGHSA enrichment
  20. 2026-07-03 17:56 UTCEG score recompute
  21. 2026-07-03 17:56 UTCGHSA enrichment
  22. 2026-07-03 06:58 UTCEG score recompute
  23. 2026-07-03 06:58 UTCGHSA enrichment
  24. 2026-07-02 20:00 UTCEG score recompute▲ 7.50
  25. 2026-07-02 20:00 UTCGHSA enrichment
Show 6 more
  1. 2026-07-01 15:07 UTCEPSS rescore
  2. 2026-06-30 23:22 UTCEPSS rescore
  3. 2026-06-30 14:32 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  4. 2026-06-29 22:18 UTCNVD update
  5. 2026-06-29 21:57 UTCEG score recompute
  6. 2026-06-29 21:57 UTCMITRE cvelistV5first tracked

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 27.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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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