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
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
CVE-2016-10518 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 378,156 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
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 |
Detection & 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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2016-10518 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2016-10518. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2016-10518 in your dependencies?
O3 Security finds CVE-2016-10518 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.