How severe is CVE-2026-51221?

CVE-2026-51221 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-51221 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-51221?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-51221 published?

CVE-2026-51221 was published on 2026-06-29 and last updated on 2026-06-30.

CVE-2026-51221

CVE-2026-51221 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-284.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-284
Published: 2026-06-29
Last modified: 2026-06-30

Description

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.

Frequently asked questions

What is CVE-2026-51221?: 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.
How severe is CVE-2026-51221?: CVE-2026-51221 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-51221 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-51221?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-51221 published?: CVE-2026-51221 was published on 2026-06-29 and last updated on 2026-06-30.

References

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