How severe is CVE-2026-8751?

CVE-2026-8751 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-8751 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-8751?

CVE-2026-8751 affects H2o. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-8751?

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.

Does CVE-2026-8751 have an EU (EUVD) identifier?

Yes. CVE-2026-8751 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30697.

When was CVE-2026-8751 published?

CVE-2026-8751 was published on 2026-05-17 and last updated on 2026-06-17.

CVE-2026-8751

CVE-2026-8751 is a high-severity vulnerability in H2o with a CVSS 3.x base score of 7.3. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.3)
CVSS v2: 7.5
CVSS v4: 5.5
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30697
Weakness: CWE-20
Affected product: H2o
Published: 2026-05-17
Last modified: 2026-06-17

Description

A security flaw has been discovered in h2oai h2o-3 up to 7402. This affects the function importBinaryModel of the file h2o-core/src/main/java/hex/Model.java of the component JAR Handler. Performing a manipulation results in deserialization. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Frequently asked questions

What is CVE-2026-8751?: A security flaw has been discovered in h2oai h2o-3 up to 7402. This affects the function importBinaryModel of the file h2o-core/src/main/java/hex/Model.java of the component JAR Handler. Performing a manipulation results in deserialization. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
How severe is CVE-2026-8751?: CVE-2026-8751 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-8751 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-8751?: CVE-2026-8751 affects H2o. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-8751?: 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.
Does CVE-2026-8751 have an EU (EUVD) identifier?: Yes. CVE-2026-8751 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30697.
When was CVE-2026-8751 published?: CVE-2026-8751 was published on 2026-05-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*

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