https://db.gcve.eu Contains only the most 10 recent entries. http://www.rssboard.org/rss-specification python-feedgen en Thu, 01 Oct 2026 18:45:07 +0000 https://db.gcve.eu/vuln/fkie_cve-2026-55107 <p>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.</p> <p>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.</p> https://db.gcve.eu/vuln/fkie_cve-2026-55107 https://db.gcve.eu/vuln/ghsa-7pwq-q9jf-539h <p><strong>Affected:</strong> RubyGems: kobako</p> <p>### Summary A guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox.</p> <p>### Details A host embeds bound &#34;Service&#34; objects that guest scripts call across the wasm boundary through the transport dispatcher. The dispatcher passed the guest-supplied method name straight to `Object#public_send` on the bound object, with no restriction to the object&#39;s own methods:</p> <p>```ruby target.public_send(method.to_sym, *args, **kwargs, &amp;block) ```</p> <p>`public_send` can invoke any public method, including Ruby&#39;s ambient reflection surface. A guest pivots through the public `send` into otherwise private Kernel methods: a dispatch request with `method = &#34;send&#34;` and `args = [:eval, &#34;&lt;ruby&gt;&#34;]` evaluates to `target.send(:eval, &#34;&lt;ruby&gt;&#34;)`, running attacker-controlled Ruby in the host. Any bound Service object is sufficient — no Service-specific behavior is required.</p> <p>### Proof of Concept A guest call equivalent to:</p> <p>``` Service.send(:eval, &#34;&lt;arbitrary host ruby&gt;&#34;) ```</p> <p>executes in the host process and can read or modify host state, spawn processes, and so on.</p> <p>### Impact Complete sandbox escape leading to remote code execution in the host process, defeating the gem&#39;s central guarantee of isolating untrusted mruby scripts. Any deployment that runs untrusted or attacker-influenced scripts is affected. All released versions (0.1.0 through 0.9.0) are vulnerable; the dispatcher carried the same unguarded `public_send` sink under three su…</p> <p><strong>Affected:</strong> RubyGems: kobako</p> <p>### Summary A guest mruby script running inside the Kobako sandbox can execute arbitrary Ruby in the host process, fully escaping the sandbox.</p> <p>### Details A host embeds bound &#34;Service&#34; objects that guest scripts call across the wasm boundary through the transport dispatcher. The dispatcher passed the guest-supplied method name straight to `Object#public_send` on the bound object, with no restriction to the object&#39;s own methods:</p> <p>```ruby target.public_send(method.to_sym, *args, **kwargs, &amp;block) ```</p> <p>`public_send` can invoke any public method, including Ruby&#39;s ambient reflection surface. A guest pivots through the public `send` into otherwise private Kernel methods: a dispatch request with `method = &#34;send&#34;` and `args = [:eval, &#34;&lt;ruby&gt;&#34;]` evaluates to `target.send(:eval, &#34;&lt;ruby&gt;&#34;)`, running attacker-controlled Ruby in the host. Any bound Service object is sufficient — no Service-specific behavior is required.</p> <p>### Proof of Concept A guest call equivalent to:</p> <p>``` Service.send(:eval, &#34;&lt;arbitrary host ruby&gt;&#34;) ```</p> <p>executes in the host process and can read or modify host state, spawn processes, and so on.</p> <p>### Impact Complete sandbox escape leading to remote code execution in the host process, defeating the gem&#39;s central guarantee of isolating untrusted mruby scripts. Any deployment that runs untrusted or attacker-influenced scripts is affected. All released versions (0.1.0 through 0.9.0) are vulnerable; the dispatcher carried the same unguarded `public_send` sink under three su…</p> https://db.gcve.eu/vuln/ghsa-7pwq-q9jf-539h