{"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":"2026-09-30T19:49:04.193Z"},"containers":{"cna":{"title":"Kobako Vulnerable to Sandbox Escape: guest eval reaches host RCE via method_missing → 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"}},"adp":[{"references":[{"url":"https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-30T19:48:55.982496Z","id":"CVE-2026-55107","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-30T19:49:04.193Z"}}]}}