CVE-2025-55009 is a high-severity (CVSS 7.1) Information Exposure vulnerability in @workos-inc/authkit-remix. A fix is available for @workos-inc/authkit-remix — see the affected versions and patch details below.
AuthKit: Sensitive auth data rendered in HTML
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-55009.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@workos-inc/authkit-remixnpmDescription
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
0.15.0changes the default behavior so the loader no longer returnssealedSession/accessToken. A secure server-side mechanism is provided to fetch an access token when needed.
Patches
Patched in v0.15.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @workos-inc/authkit-remix | all versions | 0.15.0npm install @workos-inc/authkit-remix@0.15.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @workos-inc/authkit-remix, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @workos-inc/authkit-remix to 0.15.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55009 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2025-55009 in your dependencies?
Find it across npm, including transitive dependencies.