{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-55107", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-16T14:41:54.579Z", "datePublished": "2026-09-30T17:06:00.286Z", "dateUpdated": "2026-09-30T17:06:00.286Z"}, "containers": {"cna": {"title": "Kobako Vulnerable to Sandbox Escape: guest eval reaches host RCE via method_missing \u2192 public_send (any bound Service)", "problemTypes": [{"descriptions": [{"cweId": "CWE-94", "lang": "en", "description": "CWE-94: Improper Control of Generation of Code ('Code Injection')", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-470", "lang": "en", "description": "CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 10, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h"}, {"name": "https://github.com/elct9620/kobako/commit/64f84700c81f44902bed9211318d5362f44987b3", "tags": ["x_refsource_MISC"], "url": "https://github.com/elct9620/kobako/commit/64f84700c81f44902bed9211318d5362f44987b3"}, {"name": "https://github.com/elct9620/kobako/releases/tag/v0.9.1", "tags": ["x_refsource_MISC"], "url": "https://github.com/elct9620/kobako/releases/tag/v0.9.1"}], "affected": [{"vendor": "elct9620", "product": "kobako", "versions": [{"version": ">= 0.1.0, < 0.9.1", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-30T17:06:00.286Z"}, "descriptions": [{"lang": "en", "value": "Kobako is a Ruby gem that embeds a Wasm-isolated mruby interpreter inside applications, allowing execution of untrusted Ruby scripts (LLM-generated code, user formulas, student submissions, third-party plugins) in-process without giving them access to host memory, files, network, or credentials. From version 0.1.0 to before version 0.9.1, a guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox. This issue has been patched in version 0.9.1."}], "source": {"advisory": "GHSA-7pwq-q9jf-539h", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "kobako", "vendor": "elct9620", "versions": [{"status": "affected", "version": ">= 0.1.0, < 0.9.1"}]}], "source": "[email protected]"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Kobako is a Ruby gem that embeds a Wasm-isolated mruby interpreter inside applications, allowing execution of untrusted Ruby scripts (LLM-generated code, user formulas, student submissions, third-party plugins) in-process without giving them access to host memory, files, network, or credentials. From version 0.1.0 to before version 0.9.1, a guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox. This issue has been patched in version 0.9.1."}], "id": "CVE-2026-55107", "lastModified": "2026-09-30T18:18:37.550", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 10.0, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 6.0, "source": "[email protected]", "type": "Secondary"}]}, "published": "2026-09-30T18:18:37.550", "references": [{"source": "[email protected]", "url": "https://github.com/elct9620/kobako/commit/64f84700c81f44902bed9211318d5362f44987b3"}, {"source": "[email protected]", "url": "https://github.com/elct9620/kobako/releases/tag/v0.9.1"}, {"source": "[email protected]", "url": "https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h"}], "sourceIdentifier": "[email protected]", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-94"}, {"lang": "en", "value": "CWE-470"}], "source": "[email protected]", "type": "Primary"}]}

{}

{}