GHSA-qwph-4952-7xr6
MEDIUMjsonwebtoken vulnerable to signature validation bypass due to insecure default algorithm in jwt.verify()
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.
Blast Radius
jsonwebtokenReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Overview
In versions <=8.5.1 of jsonwebtoken library, lack of algorithm definition and a falsy secret or key in the jwt.verify() function can lead to signature validation bypass due to defaulting to the none algorithm for signature verification.
Am I affected?
You will be affected if all the following are true in the jwt.verify() function:
- a token with no signature is received
- no algorithms are specified
- a falsy (e.g. null, false, undefined) secret or key is passed
How do I fix it?
Update to version 9.0.0 which removes the default support for the none algorithm in the jwt.verify() method.
Will the fix impact my users?
There will be no impact, if you update to version 9.0.0 and you don’t need to allow for the none algorithm. If you need 'none' algorithm, you have to explicitly specify that in jwt.verify() options.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | jsonwebtoken | all versions | 9.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for jsonwebtoken. 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 jsonwebtoken to 9.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qwph-4952-7xr6 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-qwph-4952-7xr6 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-qwph-4952-7xr6. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-qwph-4952-7xr6 in your dependencies?
O3 detects GHSA-qwph-4952-7xr6 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.