CVE-2020-15119 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in auth0-lock. A fix is available for auth0-lock — see the affected versions and patch details below.
DOM-based XSS in auth0-lock
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-2020-15119 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 378,567 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.
auth0-locknpmDescription
Overview
Versions before and including 11.25.1 are using dangerouslySetInnerHTML to display an informational message when used with a Passwordless or Enterprise connection.
- For Passwordless connection, the value of the input (email or phone number) is displayed back to the user while waiting for verification code input.
- For Enterprise connection, the value of the input (IdP Domain) from the Enterprise connection setup screen (Auth0 Dashboard) is displayed back to the user when the
lockwidget opens.
When Passwordless or Enterprise connection is used, the application and its users might be exposed to cross-site scripting (XSS) attacks.
Am I affected?
You are affected by this vulnerability if all of the following conditions apply:
- You are using auth0-lock
- You are using Passwordless or Enterprise connection mode
How to fix that?
Upgrade to version 11.26.3
Will this update impact my users?
The fix provided in patch will not affect your users.
Credit
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | auth0-lock | all versions | 11.26.3npm install auth0-lock@11.26.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for auth0-lock, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update auth0-lock to 11.26.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15119 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-2020-15119 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2020-15119. 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-2020-15119 in your dependencies?
O3 Security finds CVE-2020-15119 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.