CVE-2026-8751: h2oai h2o-3 JAR Model.java importBinaryModel deserialization
Vulnerability summary
CVE-2026-8751 is a critical (CVSS 9.8) Improper Input Validation vulnerability in h2o. EPSS estimates a 0.41% chance of exploitation in the next 30 days, higher than 35.2% of scored vulnerabilities. 1 public exploit is recorded.
Not severe (CVSS 6.9, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Timeline
- 17-05-2026PublishedVulnerability first disclosed.
- 18-05-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
7 scores · 2 sources · 4 versions- NVDNIST5.5MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XDiffers
- CVE.orgCNA7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:RDiffers
- NVDNIST7.5HighAV:N/AC:L/Au:N/C:P/I:P/A:P
EPSS trend
Probability
0.41%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
Decrease -0.36 pp
From 0.77% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
1 foundExploit Reference (vulnplus-note.wetolink.com)
Maturity: unknown
Weaknesses
CWE · root cause- CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
- CWE-502Deserialization of Untrusted DataThe product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
H2o1 product
- h2o≤ 7402
H2oai1 product
- h2o-37402
2 vendors · 2 products