Summary
op_panic in the base runtime can force a panic in the runtime's containing thread
Affected versions use deno_core releases that expose Deno.core.ops.op_panic to the JS runtime in the base core
This function when called triggers a manual panic in the thread containing the runtime, breaking sandboxing
It can be fixed by stubbing out the exposed op:
Deno.core.ops.op_panic = (msg) => { throw new Error(msg) };
Impact
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is GHSA-4MW5-2636-4535? GHSA-4MW5-2636-4535 is a medium-severity security vulnerability in js-sandbox (rust), affecting versions <= 0.1.6. No fixed version is listed yet.
- Which versions of js-sandbox are affected by GHSA-4MW5-2636-4535? js-sandbox (rust) versions <= 0.1.6 is affected.
- Is there a fix for GHSA-4MW5-2636-4535? No fixed version is listed for GHSA-4MW5-2636-4535 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is GHSA-4MW5-2636-4535 exploitable, and should I be worried? Whether GHSA-4MW5-2636-4535 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-4MW5-2636-4535 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.