CVE-2026-55544

Received Received - Intake

NextCRM MCP Campaign Authorization Bypass via Bearer Tokens

Publication date: 2026-07-20

Last updated on: 2026-07-20

Assigner: GitHub, Inc.

Description

NextCRM is open-source customer relationship management (CRM) software. In version 0.12.1, the MCP campaign tools expose campaign read and write operations over the network using user-generated Bearer API tokens (`nxtc__...`). The application has an authorization model that restricts normal users to campaigns they created, but multiple MCP campaign handlers ignore the authenticated user ID and query or mutate campaigns only by object ID. As a result, a low-privileged authenticated user with a valid MCP API token can enumerate all campaigns, read campaign details, update or delete campaigns owned by other users, modify campaign templates and steps, and potentially trigger or pause campaign delivery. Version 0.12.2 fixes the issue.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-20

Last Modified

2026-07-20

Generated

2026-07-21

AI Q&A

2026-07-21

EPSS Evaluated

N/A

NVD

CVE-2026-55544

Affected Vendors & Products

Vendor	Product	Version / Range
nextcrm	nextcrm	to 0.12.2 (exc)
nextcrm	nextcrm	0.12.2

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-284	The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
CWE-639	The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CWE-862	The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

Executive Summary

NextCRM 0.12.1 has a vulnerability in its MCP campaign tools where Bearer API tokens allow low-privileged users to access and modify campaigns they do not own. The application's authorization model fails to enforce user-specific restrictions, letting authenticated users query, read, update, or delete any campaign by object ID alone.

Detection Guidance

To detect this vulnerability, check if your NextCRM instance is running version 0.12.1. Inspect network traffic for MCP campaign API calls using Bearer tokens (nxtc__...). Test if low-privileged users can access or modify campaigns not owned by them by attempting to enumerate, read, update, or delete campaigns via API endpoints.

Impact Analysis

An attacker with a valid MCP API token could access sensitive campaign data, alter or delete campaigns, modify templates or steps, and disrupt campaign delivery. This could lead to data leaks, operational disruptions, or unauthorized changes affecting business processes.

Compliance Impact

This vulnerability could violate GDPR by exposing personal data in campaigns or HIPAA by compromising campaign details containing protected health information. Unauthorized access or modification of data may lead to non-compliance with data integrity and confidentiality requirements.

Mitigation Strategies

Upgrade NextCRM to version 0.12.2 or later immediately. Review and restrict API token permissions to enforce proper authorization checks. Audit campaign access logs for suspicious activity. Implement network-level controls to limit exposure of MCP campaign endpoints.

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