CVE-2026-105857: @payloadcms/plugin form builder Remote Code Execution Vulnerability

CRITICAL
Advisory Identifier: GHSA-r488-j9vj-wx3q
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CVSS 10.0
CWE-1321 CWE-94
Published
Advisory Summary

CVE-2026-105857 is a CRITICAL (CVSS 10.0) remote code execution vulnerability (CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')) affecting @payloadcms/plugin form builder libraries in the npm ecosystem. The issue involves payload form builder has an rce issue. Remediation is available by upgrading affected packages to version 3.90.0, 4.0.0-canary.34.

CVE-2026-105857 at a Glance

CVE Identifier CVE-2026-105857
GHSA Identifier GHSA-r488-j9vj-wx3q
Severity CRITICAL
CVSS v3.1 Base Score 10.0
CWE Classification CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Affected Product @payloadcms/plugin form builder
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 10.0

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

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

How to Fix CVE-2026-105857

To remediate this vulnerability, upgrade all affected @payloadcms/plugin form builder 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-form-builder fixed: 3.90.0 
npm install @payloadcms/plugin-form-builder@3.90.0
@payloadcms/plugin-form-builder fixed: 4.0.0-canary.34 
npm install @payloadcms/plugin-form-builder@4.0.0-canary.34
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-form-builder

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-105857, inspect your project dependencies using npm:

npm ls @payloadcms/plugin-form-builder

Analyze the terminal output to locate any version of @payloadcms/plugin form builder in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.90.0), your application is affected.

Note: The npm ls @payloadcms/plugin-form-builder 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-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution'), where the product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. In @payloadcms/plugin form builder, 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 A vulnerability in `@payloadcms/plugin-form-builder` in versions < 3.90.0 allow submissions which could be crafted to execute remote code on the server. **You are affected if:** - You are using `@payloadcms/plugin-form-builder` ## Patches Users should upgrade Payload packages to `>= 3.90.0` or `>= 4.0.0-canary.34`.

CVE-2026-105857 Affected @payloadcms/plugin form builder Versions

2 component(s)
Fixed Versions:
3.90.04.0.0-canary.34
Product / Package Ecosystem Affected Versions Fixed Version
@payloadcms/plugin-form-builder
npm/@payloadcms/plugin-form-builder
npm
< 3.90.0
3.90.0
@payloadcms/plugin-form-builder
npm/@payloadcms/plugin-form-builder
npm
≥ 4.0.0-canary.0
< 4.0.0-canary.34
4.0.0-canary.34

References

GitHub Advisory / Wiki ADVISORY
https://github.com/payloadcms/payload/security/advisories/GHSA-r488-j9vj-wx3q
NVD — CVE-2026-105857 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-105857
Security Fix Commit FIX COMMIT
https://github.com/payloadcms/payload/commit/333b82b9f3e685fed6826c2e3270da79df8336c6
@payloadcms/plugin form builder Source Repository REPOSITORY
https://github.com/payloadcms/payload
@payloadcms/plugin form builder Release RELEASE
https://github.com/payloadcms/payload/releases/tag/v3.90.0

Frequently Asked Questions

What is CVE-2026-105857?
CVE-2026-105857 is a security vulnerability in @payloadcms/plugin form builder involving Payload Form Builder has an RCE issue under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution').
Which @payloadcms/plugin form builder versions are affected?
Affected versions include releases prior to 3.90.0, 4.0.0-canary.34 across affected packages: @payloadcms/plugin-form-builder.
What version fixes CVE-2026-105857?
Upgrading to 3.90.0, 4.0.0-canary.34 (or the latest patched release for your respective branch) resolves the vulnerability.
Is @payloadcms/plugin-form-builder affected?
Yes, @payloadcms/plugin-form-builder is affected in releases prior to 3.90.0, 4.0.0-canary.34. Upgrade your dependency to 3.90.0, 4.0.0-canary.34 or later.
What is the CVSS score of CVE-2026-105857?
CVE-2026-105857 has a CVSS v3.1 base score of 10.0 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H.
What CWE is associated with CVE-2026-105857?
CVE-2026-105857 is classified under CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.).
How can I check npm dependencies for CVE-2026-105857?
Run the dependency tree command: 'npm ls @payloadcms/plugin-form-builder'. 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-r488-j9vj-wx3q",
  "modified" : "2026-10-07T20:28:48Z",
  "published" : "2026-10-07T20:28:33Z",
  "aliases" : [ "CVE-2026-105857" ],
  "summary" : "Payload Form Builder has an RCE issue",
  "details" : "## Impact\n\nA vulnerability in `@payloadcms/plugin-form-builder` in versions < 3.90.0 allow submissions which could be crafted to execute remote code on the server.\n\n**You are affected if:**\n\n- You are using `@payloadcms/plugin-form-builder`\n\n## Patches\n\nUsers should upgrade Payload packages to `>= 3.90.0` or `>= 4.0.0-canary.34`.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@payloadcms/plugin-form-builder"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.90.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@payloadcms/plugin-form-builder"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0-canary.0"
      }, {
        "fixed" : "4.0.0-canary.34"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/payloadcms/payload/security/advisories/GHSA-r488-j9vj-wx3q"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-105857"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/payloadcms/payload/commit/333b82b9f3e685fed6826c2e3270da79df8336c6"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/payloadcms/payload"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/payloadcms/payload/releases/tag/v3.90.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1321", "CWE-94" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-07T20:28:33Z",
    "nvd_published_at" : "2026-10-06T17:17:21Z"
  }
}