GHSA-58qx-3vcg-4xpx is a medium-severity (CVSS 4.4) CWE-908 vulnerability in ws. O3 Security confirms whether GHSA-58qx-3vcg-4xpx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
ws: Uninitialized memory disclosure
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.
Exploitation and automatability from CISA’s SSVC triage for GHSA-58qx-3vcg-4xpx.
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.
How urgent is this, really
GHSA-58qx-3vcg-4xpx plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 0 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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.
wsnpmDescription
Impact
The websocket.close() implementation is vulnerable to uninitialized memory disclosure when a TypedArray is passed as the reason argument.
Proof of concept
import { deepStrictEqual } from 'node:assert';
import { WebSocket, WebSocketServer } from 'ws';
const wss = new WebSocketServer(
{ port: 0, skipUTF8Validation: true },
function () {
const { port } = wss.address();
const ws = new WebSocket(`ws://localhost:${port}`, {
skipUTF8Validation: true
});
ws.on('close', function (code, reason) {
deepStrictEqual(reason, Buffer.alloc(80));
});
}
);
wss.on('connection', function (ws) {
ws.close(1000, new Float32Array(20));
});
Patches
The vulnerability was fixed in [email protected] (https://github.com/websockets/ws/commit/c0327ec15a54d701eb6ccefaa8bef328cfc03086).
Credits
Credit for the private and responsible disclosure of this issue goes to Nikita Skovoroda.
Remarks
Although the calculated CVSS severity is medium, the actual severity is believed to be low, as the flaw is only exploitable through misuse that is unlikely in practice.
Resources
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ws | ≥ 8.0.0&&< 8.20.1 | 8.20.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ws. 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 ws to 8.20.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-58qx-3vcg-4xpx 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-58qx-3vcg-4xpx 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-58qx-3vcg-4xpx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This Important vulnerability in the `ws` WebSocket library for Node.js could lead to sensitive information disclosure. The flaw occurs when a `TypedArray` is specifically provided as the `reason` argument to the `websocket.close()` function, potentially exposing uninitialized memory. Red Hat products utilizing this…
Frequently Asked Questions
Is GHSA-58qx-3vcg-4xpx in your dependencies?
O3 detects GHSA-58qx-3vcg-4xpx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.