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 formulas, student submissions, third-party plugins in-process without giving them access to host memory, files, network, or credentials. Fr...

CVE-2026-55107

The Kobako Ruby gem (versions 0.1.0 through 0.9.0 ) contains a critical sandbox escape vulnerability. The root cause is an unguarded Object#public_send sink in the transport dispatcher, which allows guest mruby scripts to execute arbitrary Ruby in the host process. Attackers can pivot through the...

CVE-2026-55107 Kobako Vulnerable to Sandbox Escape: guest eval reaches host RCE via method_missing → public_send (any bound Service)

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. Fr...

CVE-2026-55107 Kobako Vulnerable to Sandbox Escape: guest eval reaches host RCE via method_missing → public_send (any bound Service)

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. Fr...

EUVD-2026-90197

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. Fr...

GHSA-7PWQ-Q9JF-539H kobako Sandbox Escape: guest eval reaches host RCE via method_missing → public_send (any bound Service)

Summary A guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox. Details A host embeds bound "Service" objects that guest scripts call across the wasm boundary through the transport dispatcher. The dispatcher passed the...

kobako Sandbox Escape: guest eval reaches host RCE via method_missing → public_send (any bound Service)

Summary A guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox. Details A host embeds bound "Service" objects that guest scripts call across the wasm boundary through the transport dispatcher. The dispatcher passed the...

kobako Sandbox Escape - guest eval reaches host RCE via method_missing → public_send (any bound Service)

Summary A guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox. Impact Complete sandbox escape leading to remote code execution in the host process, defeating the gem's central guarantee of isolating untrusted mruby script...