CVE-2026-3960
criticalpriority · track · 39EPSS 0.009 · 61 %ileEUUSEPSS · scored 2026-10-27
A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTable in H2O-3 version 3.46.0.9 and prior. The vulnerability arises due to insufficient security controls in the parameter blacklist mechanism, which only targets MySQL JDBC driver-specific dangerous parameters. An attacker can bypass these controls by switching the JDBC URL protocol to jdbc:postgresql: and exploiting PostgreSQL JDBC driver-specific parameters such as socketFactory and socketFactoryArg. This allows unauthenticated attackers to execute arbitrary code on the H2O-3 server with the privileges of the H2O-3 process. The issue is resolved in version 3.46.0.10.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 5.9–9.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-qmcv-hh7c-3m56H2O-3 is Vulnerable to Code Injection2026-04-23ghsa · osvUS
A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTable in H2O-3 version 3.46.0.9 and prior. The vulnerability arises due to insufficient security controls in the parameter blacklist mechanism, which only targets MySQL JDBC driver-specific dangerous parameters. An attacker can bypass these controls by switching the JDBC URL protocol to jdbc:postgresql: and exploiting PostgreSQL JDBC driver-specific parameters such as socketFactory and socketFactoryArg. This allows unauthenticated attackers to execute arbitrary code on the H2O-3 server with the privileges of the H2O-3 process. The issue is resolved in version 3.46.0.10.
- PYSEC-2026-21802026-04-23vendor · osvUS
A critical remote code execution vulnerability exists in the unauthenticated REST API endpoint /99/ImportSQLTable in H2O-3 version 3.46.0.9 and prior. The vulnerability arises due to insufficient security controls in the parameter blacklist mechanism, which only targets MySQL JDBC driver-specific dangerous parameters. An attacker can bypass these controls by switching the JDBC URL protocol to jdbc:postgresql: and exploiting PostgreSQL JDBC driver-specific parameters such as socketFactory and socketFactoryArg. This allows unauthenticated attackers to execute arbitrary code on the H2O-3 server with the privileges of the H2O-3 process. The issue is resolved in version 3.46.0.10.
also known as (6)
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sources
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references (6)
External citations — patches, advisories, analysis.
- https://h2o.ai/Patchcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-3960cnnvd
- https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044enisa_euvd
- https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0denisa_euvd
- https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044Patchnvd
- https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0dExploitThird Party Advisorynvd
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