CVE-2026-30624: Agent Zero 0.9.8 RCE Vulnerability

CVE-2026-30624 Overview

CVE-2026-30624 is a command injection vulnerability affecting Agent Zero version 0.9.8. The vulnerability exists in the External MCP (Model Context Protocol) Servers configuration feature, which allows users to define MCP servers using JSON configuration files containing arbitrary command and args values. These values are executed by the application when the configuration is applied without sufficient validation or restriction. An attacker may supply a malicious MCP configuration to execute arbitrary operating system commands, potentially resulting in remote code execution with the privileges of the Agent Zero process.

Critical Impact

This vulnerability enables remote code execution through maliciously crafted MCP server configurations, allowing attackers to execute arbitrary commands on systems running Agent Zero with the same privileges as the application process.

Affected Products

• Agent Zero version 0.9.8

Discovery Timeline

• April 15, 2026 - CVE-2026-30624 published to NVD
• April 15, 2026 - Last updated in NVD database

Technical Details for CVE-2026-30624

Vulnerability Analysis

This vulnerability is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command), commonly known as Command Injection. The flaw resides in Agent Zero's handling of user-supplied MCP server configurations. When users configure external MCP servers, the application accepts JSON configuration data that includes command and args fields. These fields are intended to specify how the application should interact with external MCP servers, but the lack of input validation creates a dangerous attack surface.

The vulnerability allows network-based exploitation without requiring authentication or user interaction. An attacker can craft a malicious JSON configuration containing shell commands or system binaries as the command value, along with attacker-controlled arguments. When Agent Zero processes this configuration, it directly executes these values at the operating system level without sanitization, validation, or restriction to a safe list of allowed commands.

Root Cause

The root cause is insufficient input validation and lack of command whitelisting in the MCP server configuration parser. The application directly passes user-supplied configuration values to system execution functions without:

• Validating that the command field contains only expected/approved executables
• Sanitizing the args field to prevent injection of additional shell commands
• Implementing a sandbox or restricted execution environment
• Applying principle of least privilege to the execution context

Attack Vector

The attack vector is network-based, requiring an attacker to either:

1. Directly supply a malicious MCP configuration through the application's configuration interface
2. Trick a legitimate user into importing a malicious configuration file
3. Compromise a configuration source that Agent Zero trusts

Once the malicious configuration is processed, the attacker-controlled commands execute with the full privileges of the Agent Zero process. This could allow attackers to establish persistence, exfiltrate sensitive data, move laterally within the network, or deploy additional malware.

The vulnerability exploits the trust relationship between Agent Zero and its MCP server configuration. A malicious configuration would contain operating system commands in the command field (such as shell interpreters or system utilities) with malicious arguments, which are then executed without validation when the configuration is applied. For detailed technical analysis, refer to the Ox Security Blog Advisory.

Detection Methods for CVE-2026-30624

Indicators of Compromise

• Unexpected child processes spawned by the Agent Zero application process
• Unusual outbound network connections originating from the Agent Zero process
• Modified or newly created MCP configuration files with suspicious command or args values
• Evidence of shell interpreters (bash, cmd, powershell) being invoked as MCP server commands

Detection Strategies

• Monitor process execution chains for Agent Zero spawning unexpected child processes
• Implement file integrity monitoring on MCP configuration directories
• Deploy endpoint detection rules to alert on command injection patterns in configuration files
• Review application logs for configuration changes involving executable paths

Monitoring Recommendations

• Enable verbose logging for Agent Zero configuration changes and MCP server interactions
• Configure SIEM alerts for process lineage anomalies involving Agent Zero
• Monitor for unusual file system activity in Agent Zero's working directories
• Establish baselines for normal MCP server configurations and alert on deviations

How to Mitigate CVE-2026-30624

Immediate Actions Required

• Audit all existing MCP server configurations for suspicious or unexpected command values
• Restrict access to Agent Zero's configuration interface to trusted administrators only
• Implement network segmentation to limit the blast radius if exploitation occurs
• Consider temporarily disabling the External MCP Servers feature until a patch is available

Patch Information

No official patch information is currently available for this vulnerability. Organizations should monitor the Ox Security Blog Advisory and official Agent Zero release channels for security updates addressing this vulnerability.

Workarounds

• Implement strict access controls limiting who can modify MCP server configurations
• Deploy application-level firewalling to restrict Agent Zero's ability to spawn child processes
• Use containerization or sandboxing to isolate Agent Zero from critical system resources
• Review and approve all MCP configuration changes through a security review process before deployment