Summary
auth-js Vulnerable to Insecure Path Routing from Malformed User Input
Workarounds
Implementations that follow security best practice and validate user controlled inputs, such as the userId are not affected by this. It is recommended that users of the auth-js library always follow security best practice and validate all inputs, before passing these to other functions or libraries.
References
Impact
The library functions getUserById, deleteUser, updateUserById, listFactors and deleteFactor did not require the user supplied values to be valid UUIDs. This could lead to a URL path traversal, resulting in the wrong API function being called.
Implementations that follow security best practice and validate user controlled inputs, such as the userId are not affected by this.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
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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Strict value checks have been added to all affected functions. These functions now require that the userId and factorId parameters MUST be valid UUID (v4).
Patched version: >= 2.69.1
Frequently Asked Questions
- What is CVE-2025-48370? CVE-2025-48370 is a low-severity path traversal vulnerability in @supabase/auth-js (npm), affecting versions <= 2.69.1. It is fixed in 2.70.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- Which versions of @supabase/auth-js are affected by CVE-2025-48370? @supabase/auth-js (npm) versions <= 2.69.1 is affected.
- Is there a fix for CVE-2025-48370? Yes. CVE-2025-48370 is fixed in 2.70.0. Upgrade to this version or later.
- Is CVE-2025-48370 exploitable, and should I be worried? Whether CVE-2025-48370 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-2025-48370 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-2025-48370? Upgrade
@supabase/auth-jsto 2.70.0 or later.