GHSA-6jg8-7333-554w
CRITICALGHSA-6jg8-7333-554w is a critical-severity (CVSS 9.8) remote code execution vulnerability in realms-shim. O3 Security confirms whether GHSA-6jg8-7333-554w is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Sandbox Breakout in realms-shim
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
realms-shimnpmsesnpmDescription
Versions of realms-shim prior to 1.2.0 are vulnerable to a Sandbox Breakout. Reflect.construct can be used on the sandboxed Function constructor to reach the prototypes of the primal Realm, which may allow an attacker to escape the sandbox and execute arbitrary code.
Recommendation
Upgrade to version 1.2.0 or later.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | realms-shim | all versions | 1.2.0 |
| 📦npm | ses | all versions | 0.6.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for realms-shim. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update realms-shim to 1.2.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6jg8-7333-554w is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-6jg8-7333-554w is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-6jg8-7333-554w. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6jg8-7333-554w in your dependencies?
O3 detects GHSA-6jg8-7333-554w across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.