GHSA-m9hw-7xfv-wqg7 — json-logic-js
Fix: jwadhams/json-logic-js@fadfa5dGHSA-m9hw-7xfv-wqg7 is a remote code execution vulnerability in json-logic-js. A fix is available for json-logic-js — see the affected versions and patch details below.
Prototype Pollution in json-logic-js
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
json-logic-jsnpmDescription
Versions of json-logic-js prior to 2.0.0 are vulnerable to Prototype Pollution. The method operation allows a malicious user to modify the prototype of Object through the method property name. This causes modification of any existing property that will exist on all objects and leads to Remote Code Execution.
The following rule creates a popup when run from a browser:
{
"method": [
{
"method": [
{
"var": "__proto__.constructor.is.__proto__"
},
"constructor",
[
"var x = 'SECURITY!'; console.log(x, window.fetch); alert(x)"
]
]
},
"call"
]
}
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | json-logic-js | all versions | 2.0.0npm install json-logic-js@2.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for json-logic-js, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update json-logic-js to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m9hw-7xfv-wqg7 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-m9hw-7xfv-wqg7 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-m9hw-7xfv-wqg7. 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-m9hw-7xfv-wqg7 in your dependencies?
O3 Security finds GHSA-m9hw-7xfv-wqg7 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.