CVE-2020-7741 is a critical-severity (CVSS 9.9) Cross-site Scripting (XSS) vulnerability in hellojs. A fix is available for hellojs — see the affected versions and patch details below.
XSS in hello.js
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.
hellojsnpmDescription
This affects the package hellojs before 1.18.6. The code get the param oauth_redirect from url and pass it to location.assign without any check and sanitisation. So we can simply pass some XSS payloads into the url param oauth_redirect, such as javascript:alert(1).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | hellojs | all versions | 1.18.6npm install hellojs@1.18.6 |
Affected Products
hello.jshello.js_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for hellojs, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update hellojs to 1.18.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7741 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2020-7741 in your dependencies?
Find it across npm, including transitive dependencies.