CVE-2016-1000223 is a high-severity (CVSS 8.7) vulnerability in jws. A fix is available for jws — see the affected versions and patch details below.
Forgeable Public/Private Tokens in jws
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.
jwsnpmDescription
Affected versions of the jws package allow users to select what algorithm the server will use to verify a provided JWT. A malicious actor can use this behaviour to arbitrarily modify the contents of a JWT while still passing verification. For the common use case of the JWT as a bearer token, the end result is a complete authentication bypass with minimal effort.
Recommendation
Update to version 3.0.0 or later.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jws | all versions | 3.0.0npm install jws@3.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jws, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update jws to 3.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2016-1000223 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-2016-1000223 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2016-1000223. 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-2016-1000223 in your dependencies?
O3 Security finds CVE-2016-1000223 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.