CRITICAL 10.0 NVD
CVE-2026-55107
Kobako is a Ruby gem that embeds a Wasm-isolated mruby interpreter inside applications, allowing execution of untrusted Ruby scripts (LLM-generated code, user f
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.
References
- https://github.com/elct9620/kobako/commit/64f84700c81f44902bed9211318d5362f44987b3
- https://github.com/elct9620/kobako/releases/tag/v0.9.1
- https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h
- https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h
This critical severity vulnerability with a CVSS score of 10.0 was published on 2026-09-30 via NVD.
Risk Timeline
CVE Disclosed2026-09-30 · 2 days ago
Remediation Resources
vulnfeed aggregates 9972 vulnerabilities from NVD, CISA KEV,
Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.