Information disclosure through error object in auth0.js

Exploitation

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

CVSS

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

EPSS

• CVE-2020-5263: 0.87% estimated exploitation activity in the next 30 days; percentile 58.89 (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 Between versions 8.0.0 and 9.13.1(inclusive), in the case of an (authentication) error, the error object returned by the library contains the original request of the user, which may include the plaintext password the user entered. If the error object is exposed or logged without modification, the application risks password exposure. Am I affected? You are affected by this vulnerability if all of the following conditions apply: - You are using Auth0.js version between 8.0.0 and 9.13.1(inclusive). - You store or display error objects without filtering. How to fix that? Developers should upgrade auth0.js to version 9.13.2 or later where user inputted passwords are masked in errors. If upgrading is not possible, a temporary fix may include not storing the error object or displaying it publicly without modification. Will this update impact my users? This fix patches the Auth0.js and may require changes in application code due to password no longer available in error object, but…

Published by the source

10 Apr 2020, 18:19 UTC

Last modified by the source

8 Jul 2026, 06:29 UTC

Source last checked

26 Oct 2026, 12:07 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-prfq-f66g-43mp

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-prfq-f66g-43mp

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# Patch Next advisory brief: CVE-2020-5263

Advisory: Information disclosure through error object in auth0.js
IDs: CVE-2020-5263, GHSA-prfq-f66g-43mp
Record: https://patchnext.com/advisories/cve-2020-5263 (revision 2, source checked 26 Oct 2026, 12:07 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: auth0-js 9.13.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm auth0-js: affected >= 8.0.0, < 9.13.2; fixed in 9.13.2

## Suggested inspection (read-only)
- `npm ls auth0-js --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-js.
- 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-prfq-f66g-43mp (OSV record GHSA-prfq-f66g-43mp lists affected ranges: npm auth0-js >=8.0.0 <9.13.2 (fixed))
- Verified: https://github.com/advisories/GHSA-prfq-f66g-43mp (GitHub-reviewed advisory GHSA-prfq-f66g-43mp lists affected ranges: npm auth0-js >=8.0.0 <9.13.2)

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