CVE-2016-10518 is a high-severity (CVSS 7.5) CWE-201 vulnerability in ws. A fix is available for ws — see the affected versions and patch details below.
Remote Memory Disclosure in ws
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.
wsnpmDescription
Versions of ws prior to 1.0.1 are affected by a remote memory disclosure vulnerability.
In certain rare circumstances, applications which allow users to control the arguments of a client.ping() call will cause ws to send the contents of an allocated but non-zero-filled buffer to the server. This may disclose sensitive information that still exists in memory after previous use of the memory for other tasks.
Proof of Concept
var ws = require('ws')
var server = new ws.Server({ port: 9000 })
var client = new ws('ws://localhost:9000')
client.on('open', function () {
console.log('open')
client.ping(50) // this sends a non-zeroed buffer of 50 bytes
client.on('pong', function (data) {
console.log('got pong')
console.log(data) // Data from the client.
})
})
Recommendation
Update to version 1.0.1 or greater.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | ws | all versions | 1.0.1npm install ws@1.0.1 |
Affected Products
wsws_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ws, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ws to 1.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-10518 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.
Frequently Asked Questions
Is CVE-2016-10518 in your dependencies?
Find it across npm, including transitive dependencies.