CVE-2019-20174

Name: CVE-2019-20174
Creator: NVD / NIST
Published: 2020-02-03T18:15:12.053+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.72%

Last modified Jun 17, 2026

CVE-2019-20174 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. Auth0 Lock before 11.21.0 allows XSS when additionalSignUpFields is used with an untrusted placeholder.. EPSS estimates a 0.72% chance of exploitation in the next 30 days.

Description

Auth0 Lock before 11.21.0 allows XSS when additionalSignUpFields is used with an untrusted placeholder.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.72%

49.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Auth0	Lock	< 11.21.0

References

https://auth0.com/docs/security/bulletins/cve-2019-20174Exploit, Vendor Advisory
https://github.com/auth0/lock/releases/tag/v11.21.0Release Notes, Third Party Advisory
https://auth0.com/docs/security/bulletins/cve-2019-20174Exploit, Vendor Advisory
https://github.com/auth0/lock/releases/tag/v11.21.0Release Notes, Third Party Advisory

Timeline

Published: Feb 3, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-20174?

Auth0 Lock before 11.21.0 allows XSS when additionalSignUpFields is used with an untrusted placeholder.

How severe is CVE-2019-20174?

CVE-2019-20174 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.72% probability of exploitation in the next 30 days.

How do I fix CVE-2019-20174?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-20174?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST