The AuthKit Remix Library renders sensitive auth data in HTML
Date: 2025-08
Affected: npm/@workos-inc/authkit-remix
Attack vector: xss
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2025-55009
CWE: CWE-200
CVSS: 7.1 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L)

### Summary Before `0.15.0`, `@workos-inc/authkit-remix` returned sensitive authentication artifacts from the `authkitLoader`, specifically `sealedSession` and `accessToken`. Because these values were returned from the loader, they were embedded into the server-rendered HTML and became readable by any script with access to the page’s DOM (e.g., in the presence of XSS or a malicious browser extension). * **Impact:** Exposure of these secrets can lead to session hijacking and unauthorized API access. * **Fix:** Version `0.15.0` changes the default behavior so the loader no longer returns `sealedSession`/`accessToken`. A secure server-side mechanism is provided to fetch an access token when needed. ### Patches Patched in [v0.15.0](https://github.com/workos/authkit-remix/releases/tag/v0.15.0).


Mitigations:

Architectural layers (MAESTRO):