Summary
Missing proper state, nonce and PKCE checks for OAuth authentication
Workarounds
Upgrading to latest is the recommended way to fix this issue. However, using Advanced Initialization, developers can manually check the callback request for state, pkce, and nonce against the provider configuration, and abort the sign-in process if there is a mismatch. Check out the source code for help.
References
Impact
A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.
CVE-2023-27490 has a CVSS score of 8.1 (High). The vector is network-reachable, no privileges required, and user interaction required. 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 (4.20.1); 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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We patched the vulnerability in next-auth v4.20.1
To upgrade, run one of the following:
npm i next-auth@latest
yarn add next-auth@latest
pnpm add next-auth@latest
Frequently Asked Questions
- What is CVE-2023-27490? CVE-2023-27490 is a high-severity cross-site request forgery (CSRF) vulnerability in next-auth (npm), affecting versions < 4.20.1. It is fixed in 4.20.1. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
- How severe is CVE-2023-27490? CVE-2023-27490 has a CVSS score of 8.1 (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 next-auth are affected by CVE-2023-27490? next-auth (npm) versions < 4.20.1 is affected.
- Is there a fix for CVE-2023-27490? Yes. CVE-2023-27490 is fixed in 4.20.1. Upgrade to this version or later.
- Is CVE-2023-27490 exploitable, and should I be worried? Whether CVE-2023-27490 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-2023-27490 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-2023-27490? Upgrade
next-authto 4.20.1 or later.