What’s Vulnerable › Vulnerabilities

CVE-2021-32641: Reflected XSS when using flashMessages

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.5% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-06-04 · updated 2026-06-17
• Weakness: CWE-79

Description

auth0-lock is Auth0's signin solution. Versions of nauth0-lock before and including `11.30.0` are vulnerable to reflected XSS. An attacker can execute arbitrary code when the library's `flashMessage` feature is utilized and user input or data from URL parameters is incorporated into the `flashMessage` or the library's `languageDictionary` feature is utilized and user input or data from URL parameters is incorporated into the `languageDictionary`. The vulnerability is patched in version 11.30.1.

Affected products

• auth0 lock: before 11.30.1 — fixed in 11.30.1

How to fix

Upgrade to a fixed version: auth0 lock 11.30.1. Check the vendor advisory for mitigations.

References

• https://github.com/auth0/lock/commit/d139cf01c8234b07caf265e051f39d3eab08f7ed
• https://github.com/auth0/lock/releases/tag/v11.30.1
• https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm
• https://github.com/auth0/lock/commit/d139cf01c8234b07caf265e051f39d3eab08f7ed
• https://github.com/auth0/lock/releases/tag/v11.30.1
• https://github.com/auth0/lock/security/advisories/GHSA-jr3j-whm4-9wwm

Get alerted when CVE-2021-32641 or the next vulnerability affects your stack