CVE-2026-33326: @keystone-6/core `isFilterable` Bypass Vulnerability

MODERATE
Advisory Identifier: GHSA-cgcg-q9jh-5pr2
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CVSS 4.3
CWE-863
Published
Advisory Summary

CVE-2026-33326 is a MODERATE (CVSS 4.3) `isfilterable` bypass vulnerability (CWE-863: Incorrect Authorization) affecting @keystone-6/core libraries in the npm ecosystem. The issue involves `isfilterable` bypass via `cursor` parameter in findmany (cve-2025-46720 incomplete fix). Remediation is available by upgrading affected packages to version 6.5.2.

CVE-2026-33326 at a Glance

CVE Identifier CVE-2026-33326
GHSA Identifier GHSA-cgcg-q9jh-5pr2
Severity MODERATE
CVSS v3.1 Base Score 4.3
CWE Classification CWE-863: Incorrect Authorization
Affected Product @keystone-6/core
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 4.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-33326

To remediate this vulnerability, upgrade all affected @keystone-6/core dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

@keystone-6/core fixed: 6.5.2 
npm install @keystone-6/core@6.5.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls @keystone-6/core

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-33326, inspect your project dependencies using npm:

npm ls @keystone-6/core

Analyze the terminal output to locate any version of @keystone-6/core in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.5.2), your application is affected.

Note: The npm ls @keystone-6/core command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In @keystone-6/core, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

# Summary `{field}.isFilterable` access control can be bypassed in `findMany` queries by passing a `cursor`. This can be used to confirm the existence of records by protected field values. The fix for [CVE-2025-46720](https://github.com/keystonejs/keystone/security/advisories/GHSA-hg9m-67mm-7pg3) (field-level `isFilterable` bypass for update and delete mutations) added checks to the `where` parameter in `update` and `delete` mutations however the `cursor` parameter in `findMany` was not patched and accepts the same `UniqueWhere` input type. # Impact This affects any project relying on `isFilterable` behaviour (at the list or field level) to prevent external users from using the filtering of fields as a discovery mechanism. `isFilterable` access control using a function can be bypassed by using the `cursor` input. This has no impact on projects using `isFilterable: false` or `defaultIsFilterable: false` for sensitive fields, or if you have otherwise omitted filtering by these fields from your GraphQL schema. (See workarounds) # Patches This issue has been patched in `@keystone-6/core` version 6.5.2. # Workarounds To mitigate this issue in older versions where patching is not a viable pathway. - Set `{field}.isFilterable: false` statically for relevant fields to prevent filtering by them earlier in the access control pipeline (that is, don't use functions) - Set `{field}.graphql.omit.read: true` for relevant fields, which implicitly removes filtering by these fields your GraphQL schema

CVE-2026-33326 Affected @keystone-6/core Versions

1 component(s)
Fixed Versions:
6.5.2
Product / Package Ecosystem Affected Versions Fixed Version
@keystone-6/core
npm/@keystone-6/core
npm
< 6.5.2
6.5.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/keystonejs/keystone/security/advisories/GHSA-cgcg-q9jh-5pr2
NVD — CVE-2026-33326 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33326
@keystone-6/core Source Repository REPOSITORY
https://github.com/keystonejs/keystone

Frequently Asked Questions

What is CVE-2026-33326?
CVE-2026-33326 is a security vulnerability in @keystone-6/core involving `isFilterable` bypass via `cursor` parameter in findMany (CVE-2025-46720 incomplete fix) under CWE-863: Incorrect Authorization.
Which @keystone-6/core versions are affected?
Affected versions include releases prior to 6.5.2 across affected packages: @keystone-6/core.
What version fixes CVE-2026-33326?
Upgrading to 6.5.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @keystone-6/core affected?
Yes, @keystone-6/core is affected in releases prior to 6.5.2. Upgrade your dependency to 6.5.2 or later.
What is the CVSS score of CVE-2026-33326?
CVE-2026-33326 has a CVSS v3.1 base score of 4.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-33326?
CVE-2026-33326 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check npm dependencies for CVE-2026-33326?
Run the dependency tree command: 'npm ls @keystone-6/core'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cgcg-q9jh-5pr2",
  "modified" : "2026-03-27T21:57:29Z",
  "published" : "2026-03-19T18:37:42Z",
  "aliases" : [ "CVE-2026-33326" ],
  "summary" : "@keystone-6/core: `isFilterable` bypass via `cursor` parameter in findMany (CVE-2025-46720 incomplete fix)",
  "details" : "# Summary  \n`{field}.isFilterable` access control can be bypassed in `findMany` queries by passing a `cursor`.  This can be used to confirm the existence of records by protected field values.\n\nThe fix for [CVE-2025-46720](https://github.com/keystonejs/keystone/security/advisories/GHSA-hg9m-67mm-7pg3) (field-level `isFilterable` bypass for update and delete mutations) added checks to the `where` parameter in `update` and `delete` mutations however the `cursor` parameter in `findMany` was not patched and accepts the same `UniqueWhere` input type.\n\n# Impact  \nThis affects any project relying on `isFilterable` behaviour (at the list or field level) to prevent external users from using the filtering of fields as a discovery mechanism. `isFilterable` access control using a function can be bypassed by using the `cursor` input.\n\nThis has no impact on projects using `isFilterable: false` or `defaultIsFilterable: false` for sensitive fields, or if you have otherwise omitted filtering by these fields from your GraphQL schema. (See workarounds)\n\n# Patches  \nThis issue has been patched in `@keystone-6/core` version 6.5.2.\n\n# Workarounds  \nTo mitigate this issue in older versions where patching is not a viable pathway.\n\n- Set `{field}.isFilterable: false` statically for relevant fields to prevent filtering by them earlier in the access control pipeline (that is, don't use functions)\n- Set `{field}.graphql.omit.read: true` for relevant fields, which implicitly removes filtering by these fields your GraphQL schema",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@keystone-6/core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.5.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.5.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/keystonejs/keystone/security/advisories/GHSA-cgcg-q9jh-5pr2"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-33326"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/keystonejs/keystone"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-19T18:37:42Z",
    "nvd_published_at" : "2026-03-24T20:16:28Z"
  }
}