CVE-2026-55107
kobako Sandbox Escape - guest eval reaches host RCE via method_missing → public_send (any bound Service)
Sévérité par source
Le label propre à Trivy est CRITICAL. Critique selon GHSA, Ruby Advisory DB.
Description
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.
Paquets affectés et versions corrigées
| Source | Paquet | Corrigé en |
|---|---|---|
| rubygems::GitHub Security Advisory RubyGems | kobako | 0.9.1 |
| rubygems::Ruby Advisory Database | kobako | >= 0.9.1 |
Références
- https://advisories.gitlab.com/gem/kobako/CVE-2026-55107
- https://github.com/advisories/GHSA-7pwq-q9jf-539h
- https://github.com/elct9620/kobako
- https://github.com/elct9620/kobako/blob/main/CHANGELOG.md#091-2026-06-11
- https://github.com/elct9620/kobako/commit/64f84700c81f44902bed9211318d5362f44987b3
- https://github.com/elct9620/kobako/commit/dd081665f368f7ba54e476c3ad045ee1aa8ed703
- https://github.com/elct9620/kobako/releases/tag/v0.9.1
- https://github.com/elct9620/kobako/security/advisories/GHSA-7pwq-q9jf-539h