CVE-2026-105806: Payload Improper Access Control For MCP Vulnerability

HIGH
Advisory Identifier: GHSA-2q76-m6w6-qgc6
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CWE-862
Published
Advisory Summary

CVE-2026-105806 is a HIGH improper access control for mcp vulnerability (CWE-862: Missing Authorization) affecting Payload libraries in the npm ecosystem. The issue involves improper access control for mcp api keys. Remediation is available by upgrading affected packages to version 3.88.0.

CVE-2026-105806 at a Glance

CVE Identifier CVE-2026-105806
GHSA Identifier GHSA-2q76-m6w6-qgc6
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-862: Missing Authorization
Affected Product Payload
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-105806

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

@payloadcms/plugin-mcp fixed: 3.88.0 
npm install @payloadcms/plugin-mcp@3.88.0
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 @payloadcms/plugin-mcp

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-105806, inspect your project dependencies using npm:

npm ls @payloadcms/plugin-mcp

Analyze the terminal output to locate any version of Payload in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.88.0), your application is affected.

Note: The npm ls @payloadcms/plugin-mcp 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-862: Missing Authorization, where the product does not perform an authorization check when an actor attempts to access a resource or perform an action. In Payload, 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

### Impact Under certain conditions, an authenticated user could manage MCP API keys outside their intended account allowing an attacker to escalate privileges through account takeover. Applications that do not use `@payloadcms/plugin-mcp` are not affected. ### Patches Users should upgrade to `@payloadcms/plugin-mcp` version `3.88.0` or later. ### Workarounds Upgrading is recommended. Until then, disable the MCP plugin or restrict MCP API-key management to trusted users.

CVE-2026-105806 Affected Payload Versions

1 component(s)
Fixed Versions:
3.88.0
Product / Package Ecosystem Affected Versions Fixed Version
@payloadcms/plugin-mcp
npm/@payloadcms/plugin-mcp
npm
≥ 3.61.0
< 3.88.0
3.88.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/payloadcms/payload/security/advisories/GHSA-2q76-m6w6-qgc6
Security Fix Commit FIX COMMIT
https://github.com/payloadcms/payload/commit/025581d8c5ed836039ad85397288a30f0d3c11c1
Payload Source Repository REPOSITORY
https://github.com/payloadcms/payload
Payload Release RELEASE
https://github.com/payloadcms/payload/releases/tag/v3.88.0

Frequently Asked Questions

What is CVE-2026-105806?
CVE-2026-105806 is a security vulnerability in Payload involving Improper access control for MCP API keys under CWE-862: Missing Authorization.
Which Payload versions are affected?
Affected versions include releases prior to 3.88.0 across affected packages: @payloadcms/plugin-mcp.
What version fixes CVE-2026-105806?
Upgrading to 3.88.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @payloadcms/plugin-mcp affected?
Yes, @payloadcms/plugin-mcp is affected in releases prior to 3.88.0. Upgrade your dependency to 3.88.0 or later.
What CWE is associated with CVE-2026-105806?
CVE-2026-105806 is classified under CWE-862: Missing Authorization (The product does not perform an authorization check when an actor attempts to access a resource or perform an action.).
How can I check npm dependencies for CVE-2026-105806?
Run the dependency tree command: 'npm ls @payloadcms/plugin-mcp'. 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-2q76-m6w6-qgc6",
  "modified" : "2026-10-06T16:09:31Z",
  "published" : "2026-10-06T16:09:31Z",
  "aliases" : [ "CVE-2026-105806" ],
  "summary" : "Payload: Improper access control for MCP API keys",
  "details" : "### Impact\nUnder certain conditions, an authenticated user could manage MCP API keys outside their intended account allowing an attacker to escalate privileges through account takeover.\n\nApplications that do not use `@payloadcms/plugin-mcp` are not affected.\n\n### Patches\nUsers should upgrade to `@payloadcms/plugin-mcp` version `3.88.0` or later.\n\n### Workarounds\nUpgrading is recommended. Until then, disable the MCP plugin or restrict MCP API-key management to trusted users.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@payloadcms/plugin-mcp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.61.0"
      }, {
        "fixed" : "3.88.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/payloadcms/payload/security/advisories/GHSA-2q76-m6w6-qgc6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/payloadcms/payload/commit/025581d8c5ed836039ad85397288a30f0d3c11c1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/payloadcms/payload"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/payloadcms/payload/releases/tag/v3.88.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-862" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-06T16:09:31Z",
    "nvd_published_at" : null
  }
}