Reflected XSS when using flashMessages or languageDictionary

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2021-32641: 1.54% estimated exploitation activity in the next 30 days; percentile 74.92 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Overview Versions 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. - languageDictionary feature is utilized and user input or data from URL parameters is incorporated into the languageDictionary. Am I affected? You are affected by this vulnerability if you are using auth0-lock version 11.30.0 or lower and all of the following conditions apply: - You are utilizing flashMessage feature. - User input or data from URL parameters is incorporated into the flashMessage. An example of a vulnerable snippet where query parameters are used to populate the text property of a flashMessage. OR - You are utilizing languageDictionary feature. - User input or data from URL parameters is used in languageDictionary properties. An example of a vulnerable snippet where query parameters are used to populate the…

Published by the source

4 Jun 2021, 19:10 UTC

Last modified by the source

8 Jul 2026, 06:00 UTC

Source last checked

26 Oct 2026, 12:20 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-jr3j-whm4-9wwm

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-jr3j-whm4-9wwm

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2021-32641

Advisory: Reflected XSS when using flashMessages or languageDictionary
IDs: CVE-2021-32641, GHSA-jr3j-whm4-9wwm
Record: https://patchnext.com/advisories/cve-2021-32641 (revision 2, source checked 26 Oct 2026, 12:20 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: auth0-lock 11.30.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm auth0-lock: affected < 11.30.1; fixed in 11.30.1

## Suggested inspection (read-only)
- `npm ls auth0-lock --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on auth0-lock.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-jr3j-whm4-9wwm (OSV record GHSA-jr3j-whm4-9wwm lists affected ranges: npm auth0-lock >=0 <11.30.1 (fixed))
- Verified: https://github.com/advisories/GHSA-jr3j-whm4-9wwm (GitHub-reviewed advisory GHSA-jr3j-whm4-9wwm lists affected ranges: npm auth0-lock >=0 <11.30.1)

Commands are suggestions: review each one before running it.