CVE-2023-40027 | Conditionally missing authorization in @keystone-6/core

Keystone is an open source headless CMS for Node.js — built with GraphQL and React. When `ui.isAccessAllowed` is set as `undefined`, the `adminMeta` GraphQL query is publicly accessible (no session required). This is different to the behaviour of the default AdminUI middleware, which by default will only be publicly accessible (no session required) if a `session` strategy is not defined. 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, `isAccessAllowed` is not `undefined`). This vulnerability does affect users who believed 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. This vulnerability has been patched in `@keystone-6/core` version `5.5.1`. Users are advised to upgrade. Users unable to upgrade may opt to write their own `isAccessAllowed` functionality to work-around this vulnerability.

Published: 2023-08-15 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-40027 is rated Low Risk (31.9/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.26%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-40027

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.24% 0.26% +0.01%
2 2025-11-18 0.26% 0.24% -0.01%
3 2025-04-15 — 0.26% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-40027

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.7 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-40027

GitHub Security Advisory for CVE-2023-40027

GHSA-9cvc-v7wm-992c · Severity: medium · Ecosystem: npm — When `ui.isAccessAllowed` is `undefined`, the `adminMeta` GraphQL query is publicly accessible

Affected software / configurations for CVE-2023-40027

Vendor Product Version Raw CPE
keystonejs keystone < 5.5.1 cpe:2.3:a:keystonejs:keystone:*:*:*:*:*:node.js:*:*

References for CVE-2023-40027

cvelogic Threat Intelligence