CVE-2023-40027

When ui.isAccessAllowed is undefined, the adminMeta GraphQL query is publicly accessible, that is to say, no session is required for the query.

This is different to the behaviour of the default AdminUI middleware, which by default will only be publicly accessible if a session strategy is not defined.

Workarounds

You can opt to write your own isAccessAllowed to work-around this vulnerability.

References

Pull request https://github.com/keystonejs/keystone/pull/8771

This vulnerability does not affect developers using the @keystone-6/auth package, or any users that have written their own ui.isAccessAllowed (that is to say, you are unaffected if ui.isAccessAllowed is defined).

This vulnerability does affect developers who thought that their session strategy will, by default, enforce that adminMeta is inaccessible by the public in accordance with that strategy; akin to the behaviour of the AdminUI middleware.

The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.

CVE-2023-40027 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no 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 (5.5.1); upgrading removes the vulnerable code path.

Kodem intelligence

This vulnerability has been patched in @keystone-6/core version 5.5.1.

1. What is CVE-2023-40027? CVE-2023-40027 is a medium-severity missing authorization vulnerability in @keystone-6/core (npm), affecting versions < 5.5.1. It is fixed in 5.5.1. The application does not perform an authorization check before performing a sensitive operation.
2. How severe is CVE-2023-40027? CVE-2023-40027 has a CVSS score of 5.3 (Medium). 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.
3. Which versions of @keystone-6/core are affected by CVE-2023-40027? @keystone-6/core (npm) versions < 5.5.1 is affected.
4. Is there a fix for CVE-2023-40027? Yes. CVE-2023-40027 is fixed in 5.5.1. Upgrade to this version or later.
5. Is CVE-2023-40027 exploitable, and should I be worried? Whether CVE-2023-40027 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
6. What actually determines whether CVE-2023-40027 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.
7. How do I fix CVE-2023-40027? Upgrade @keystone-6/core to 5.5.1 or later.

Other vulnerabilities in @keystone-6/core