CVE-2026-5379: runZero Platform Auth Bypass Vulnerability

CVE-2026-5379 Overview

An authorization bypass vulnerability has been identified in the runZero Platform that allowed MCP (Management Control Protocol) agents to access certificate information from outside of their authorized organization scope. This vulnerability represents an incorrect authorization issue (CWE-863) where access control mechanisms failed to properly restrict certificate data access to the appropriate organizational boundaries.

Critical Impact
MCP agents could potentially access sensitive certificate information belonging to other organizations, leading to unauthorized disclosure of security-related data across organizational boundaries.

Affected Products

runZero Platform versions prior to 4.0.260203.0

Discovery Timeline

2026-04-07 - CVE CVE-2026-5379 published to NVD
2026-04-08 - Last updated in NVD database

Technical Details for CVE-2026-5379

Vulnerability Analysis

This vulnerability stems from improper authorization controls within the runZero Platform's MCP agent certificate handling functionality. The flaw allowed authenticated MCP agents operating within one organization's scope to query and retrieve certificate information that should have been restricted to other organizations. This cross-organizational data exposure represents a breach of the platform's multi-tenant security model.

The attack requires network access and high privileges (authenticated MCP agent access), combined with high attack complexity to successfully exploit. While the scope is changed (meaning the vulnerable component can affect resources beyond its security scope), the confidentiality impact is limited and there is no impact to integrity or availability of the affected systems.

Root Cause

The root cause is classified as CWE-863: Incorrect Authorization. The runZero Platform's authorization logic failed to properly validate organization scope boundaries when MCP agents requested certificate information. This allowed agents to bypass intended access restrictions and retrieve certificate data belonging to organizations outside their authorized scope.

Attack Vector

The vulnerability is exploitable over the network by an authenticated attacker with high privileges (MCP agent access). The attack complexity is high, indicating that successful exploitation requires specific conditions or additional information gathering. No user interaction is required for exploitation.

The attack scenario involves an MCP agent that has been authenticated to the runZero Platform making requests for certificate information while manipulating or bypassing the organization scope validation. Due to the incorrect authorization controls, the platform would return certificate data from organizations the agent was not authorized to access.

Detection Methods for CVE-2026-5379

Indicators of Compromise

Unusual MCP agent queries for certificate information across multiple organization scopes
Audit log entries showing certificate access requests from agents for organizations outside their assigned scope
Anomalous patterns in certificate retrieval API calls from individual MCP agents

Detection Strategies

Monitor runZero Platform audit logs for cross-organizational certificate access attempts
Implement alerting on MCP agent activity that spans multiple organization boundaries
Review historical logs for certificate information requests that resulted in data from unexpected organizations

Monitoring Recommendations

Enable comprehensive audit logging for all MCP agent certificate-related operations
Configure alerts for any certificate access attempts that cross organizational boundaries
Regularly review MCP agent permissions and organization scope assignments

How to Mitigate CVE-2026-5379

Immediate Actions Required

Upgrade the runZero Platform to version 4.0.260203.0 or later immediately
Review audit logs for any evidence of exploitation prior to patching
Verify MCP agent organization scope assignments are correctly configured
Consider temporarily restricting MCP agent certificate access until patching is complete

Patch Information

runZero has addressed this vulnerability in version 4.0.260203.0 of the runZero Platform. Organizations should upgrade to this version or later to remediate the issue. Detailed patch information is available in the runZero Release Notes and the runZero Security Advisory for CVE-2026-5379.

Workarounds

Restrict network access to MCP agent endpoints to trusted networks only
Implement additional network segmentation between organizational boundaries
Monitor and audit all MCP agent certificate access requests until patching can be completed
Consider disabling MCP agent certificate access functionality if not business-critical

bash

# Verify runZero Platform version after upgrade
runzero --version
# Expected output: 4.0.260203.0 or higher