Summary
The AuthKit Remix Library renders sensitive auth data in HTML
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
0.15.0changes the default behavior so the loader no longer returnssealedSession/accessToken. A secure server-side mechanism is provided to fetch an access token when needed.
Impact
CVE-2025-55009 has a CVSS score of 7.1 (High). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.15.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Patched in v0.15.0.
Frequently Asked Questions
- What is CVE-2025-55009? CVE-2025-55009 is a high-severity security vulnerability in @workos-inc/authkit-remix (npm), affecting versions < 0.15.0. It is fixed in 0.15.0.
- How severe is CVE-2025-55009? CVE-2025-55009 has a CVSS score of 7.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of @workos-inc/authkit-remix are affected by CVE-2025-55009? @workos-inc/authkit-remix (npm) versions < 0.15.0 is affected.
- Is there a fix for CVE-2025-55009? Yes. CVE-2025-55009 is fixed in 0.15.0. Upgrade to this version or later.
- Is CVE-2025-55009 exploitable, and should I be worried? Whether CVE-2025-55009 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-55009 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-55009? Upgrade
@workos-inc/authkit-remixto 0.15.0 or later.