CVE-2025-55009: 
JavaScript vulnerability analysis and mitigation

CVE-2025-55009 affects the @workos-inc/authkit-remix library in versions before 0.15.0. The vulnerability was discovered and disclosed on August 8, 2025, and involves the exposure of sensitive authentication artifacts, specifically sealedSession and accessToken, by returning them from the authkitLoader which caused them to be rendered into the browser HTML (GitHub Advisory).

The vulnerability is classified as a security flaw with a CVSS v3.1 base score of 7.1 (High). The CVSS vector string is CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L, indicating network attack vector, high attack complexity, low privileges required, no user interaction needed, unchanged scope, and high impact on confidentiality and integrity with low impact on availability (GitHub Advisory).

The exposure of authentication artifacts could lead to session hijacking in environments where cross-site scripting (XSS), malicious browser extensions, or local inspection is possible. This could potentially allow attackers to gain unauthorized access to user sessions and sensitive data (GitHub Advisory).

The vulnerability has been patched in version 0.15.0 of @workos-inc/authkit-remix. The fix removes the automatic return of sealedSession and accessToken from the authkitLoader and introduces a secure server-side mechanism to fetch access tokens as needed. Users should upgrade to version 0.15.0 or later to address this vulnerability (GitHub Release).