CVE-2026-30822

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.0.13, unauthenticated users can inject arbitrary values into internal database fields when creating leads. This issue has been patched in version 3.0.13.

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.0.13, unauthenticated users can inject arbitrary values into internal database fields when creating leads. This issue has been patched in version 3.0.13.

Summary

A Mass Assignment vulnerability in the /api/v1/leads endpoint allows any unauthenticated user to control internal entity fields (id, createdDate, chatId) by including them in the request body.

The endpoint uses Object.assign() to copy all properties from the request body to the Lead entity without any input validation or field filtering. This allows attackers to bypass auto-generated fields and inject arbitrary values.

| Field | Value | |-------|-------| | Vulnerability Type | Mass Assignment | | CWE ID | CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes | | Authentication Required | None | | Affected Endpoint | POST /api/v1/leads |

Details

Root Cause

The vulnerability exists in /packages/server/src/services/leads/index.ts at lines 27-28:

// File: /packages/server/src/services/leads/index.ts
// Lines 23-38

const createLead = async (body: Partial<ILead>) => {
    try {
        const chatId = body.chatId ?? uuidv4()

        const newLead = new Lead()
        Object.assign(newLead, body)  // ← VULNERABILITY: All properties copied!
        Object.assign(newLead, { chatId })

        const appServer = getRunningExpressApp()
        const lead = appServer.AppDataSource.getRepository(Lead).create(newLead)
        const dbResponse = await appServer.AppDataSource.getRepository(Lead).save(lead)
        return dbResponse
    } catch (error) {
        throw new InternalFlowiseError(...)
    }
}

The Object.assign(newLead, body) on line 28 copies ALL properties from the request body to the Lead entity, including:

• id - The primary key (should be auto-generated)
• createdDate - The creation timestamp (should be auto-generated)
• chatId - The chat identifier

Lead Entity Definition

The Lead entity at /packages/server/src/database/entities/Lead.ts uses TypeORM decorators that should auto-generate these fields:

// File: /packages/server/src/database/entities/Lead.ts

@Entity()
export class Lead implements ILead {
    @PrimaryGeneratedColumn('uuid')  // Should be auto-generated!
    id: string

    @Column()
    name?: string

    @Column()
    email?: string

    @Column()
    phone?: string

    @Column()
    chatflowid: string

    @Column()
    chatId: string

    @CreateDateColumn()  // Should be auto-generated!
    createdDate: Date
}

However, Object.assign() overwrites these fields before they are saved, bypassing the auto-generation.

Why the Endpoint is Publicly Accessible

The /api/v1/leads endpoint is whitelisted in /packages/server/src/utils/constants.ts:

// File: /packages/server/src/utils/constants.ts
// Line 20

export const WHITELIST_URLS = [
    // ... other endpoints ...
    '/api/v1/leads',  // ← No authentication required
    // ... more endpoints ...
]

Proof of Concept

<img width="1585" height="817" alt="Screenshot 2025-12-26 at 2 28 00 PM" src="https://github.com/user-attachments/assets/807984e7-ae4f-4e8a-85b7-057d6ac42ff5" />

Prerequisites

• Docker and Docker Compose installed
• curl installed

Step 1: Start Flowise

Create a docker-compose.yml:

services:
  flowise:
    image: flowiseai/flowise:latest
    restart: unless-stopped
    environment:
      - PORT=3000
      - DATABASE_PATH=/root/.flowise
      - DATABASE_TYPE=sqlite
      - CORS_ORIGINS=*
      - DISABLE_FLOWISE_TELEMETRY=true
    ports:
      - '3000:3000'
    volumes:
      - flowise_data:/root/.flowise
    entrypoint: /bin/sh -c "sleep 3; flowise start"

volumes:
  flowise_data:

Start the container:

docker compose up -d
# Wait for Flowise to be ready (about 1-2 minutes)
curl http://localhost:3000/api/v1/ping

Step 2: Baseline Test - Normal Lead Creation

First, create a normal lead to see expected behavior:

curl -X POST…

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.0.13, unauthenticated users can inject arbitrary values into internal database fields when creating leads. This issue has been patched in version 3.0.13.

Flowise is a drag & drop user interface to build a customized large language model flow. Prior to version 3.0.13, unauthenticated users can inject arbitrary values into internal database fields when creating leads. This issue has been patched in version 3.0.13.

Summary

A Mass Assignment vulnerability in the /api/v1/leads endpoint allows any unauthenticated user to control internal entity fields (id, createdDate, chatId) by including them in the request body.

The endpoint uses Object.assign() to copy all properties from the request body to the Lead entity without any input validation or field filtering. This allows attackers to bypass auto-generated fields and inject arbitrary values.

| Field | Value | |-------|-------| | Vulnerability Type | Mass Assignment | | CWE ID | CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes | | Authentication Required | None | | Affected Endpoint | POST /api/v1/leads |

Details

Root Cause

The vulnerability exists in /packages/server/src/services/leads/index.ts at lines 27-28:

// File: /packages/server/src/services/leads/index.ts
// Lines 23-38

const createLead = async (body: Partial<ILead>) => {
    try {
        const chatId = body.chatId ?? uuidv4()

        const newLead = new Lead()
        Object.assign(newLead, body)  // ← VULNERABILITY: All properties copied!
        Object.assign(newLead, { chatId })

        const appServer = getRunningExpressApp()
        const lead = appServer.AppDataSource.getRepository(Lead).create(newLead)
        const dbResponse = await appServer.AppDataSource.getRepository(Lead).save(lead)
        return dbResponse
    } catch (error) {
        throw new InternalFlowiseError(...)
    }
}

The Object.assign(newLead, body) on line 28 copies ALL properties from the request body to the Lead entity, including:

• id - The primary key (should be auto-generated)
• createdDate - The creation timestamp (should be auto-generated)
• chatId - The chat identifier

Lead Entity Definition

The Lead entity at /packages/server/src/database/entities/Lead.ts uses TypeORM decorators that should auto-generate these fields:

// File: /packages/server/src/database/entities/Lead.ts

@Entity()
export class Lead implements ILead {
    @PrimaryGeneratedColumn('uuid')  // Should be auto-generated!
    id: string

    @Column()
    name?: string

    @Column()
    email?: string

    @Column()
    phone?: string

    @Column()
    chatflowid: string

    @Column()
    chatId: string

    @CreateDateColumn()  // Should be auto-generated!
    createdDate: Date
}

However, Object.assign() overwrites these fields before they are saved, bypassing the auto-generation.

Why the Endpoint is Publicly Accessible

The /api/v1/leads endpoint is whitelisted in /packages/server/src/utils/constants.ts:

// File: /packages/server/src/utils/constants.ts
// Line 20

export const WHITELIST_URLS = [
    // ... other endpoints ...
    '/api/v1/leads',  // ← No authentication required
    // ... more endpoints ...
]

Proof of Concept

<img width="1585" height="817" alt="Screenshot 2025-12-26 at 2 28 00 PM" src="https://github.com/user-attachments/assets/807984e7-ae4f-4e8a-85b7-057d6ac42ff5" />

Prerequisites

• Docker and Docker Compose installed
• curl installed

Step 1: Start Flowise

Create a docker-compose.yml:

services:
  flowise:
    image: flowiseai/flowise:latest
    restart: unless-stopped
    environment:
      - PORT=3000
      - DATABASE_PATH=/root/.flowise
      - DATABASE_TYPE=sqlite
      - CORS_ORIGINS=*
      - DISABLE_FLOWISE_TELEMETRY=true
    ports:
      - '3000:3000'
    volumes:
      - flowise_data:/root/.flowise
    entrypoint: /bin/sh -c "sleep 3; flowise start"

volumes:
  flowise_data:

Start the container:

docker compose up -d
# Wait for Flowise to be ready (about 1-2 minutes)
curl http://localhost:3000/api/v1/ping

Step 2: Baseline Test - Normal Lead Creation

First, create a normal lead to see expected behavior:

curl -X POST…