CVE-2026-0757 Overview
CVE-2026-0757 is a command injection vulnerability in MCP Manager for Claude Desktop that enables remote attackers to bypass the sandbox and execute arbitrary code. This vulnerability exists within the processing of MCP config objects, where improper validation of user-supplied strings before system calls allows sandbox escape and code execution at medium integrity.
User interaction is required to exploit this vulnerability—the target must visit a malicious page or open a malicious file. Once exploited, an attacker can escape the sandbox environment and execute arbitrary code in the context of the current process.
Critical Impact
Remote attackers can bypass sandbox protections and achieve arbitrary code execution through command injection in MCP config object processing, potentially compromising system integrity.
Affected Products
- MCP Manager for Claude Desktop (all versions prior to patch)
Discovery Timeline
- 2026-01-23 - CVE CVE-2026-0757 published to NVD
- 2026-01-26 - Last updated in NVD database
Technical Details for CVE-2026-0757
Vulnerability Analysis
This vulnerability (CWE-78: OS Command Injection) exists in MCP Manager for Claude Desktop's handling of MCP config objects. The application fails to properly sanitize user-supplied strings before passing them to system call functions, creating a command injection vector. The flaw specifically manifests in the execute-command functionality, where malicious input can break out of the intended command context and execute attacker-controlled system commands.
The vulnerability was originally tracked as ZDI-CAN-27810 by the Zero Day Initiative. Since exploitation requires user interaction (visiting a malicious page or opening a malicious file), the attack relies on social engineering to deliver the malicious payload. However, once triggered, the sandbox escape allows code execution at medium integrity within the current process context.
Root Cause
The root cause is insufficient input validation and sanitization of user-controlled data within MCP config object processing. When the application processes configuration objects, it directly incorporates user-supplied strings into system calls without proper escaping or validation, enabling command injection attacks that bypass sandbox restrictions.
Attack Vector
The attack vector is network-based and requires user interaction. An attacker crafts a malicious webpage or file containing specially crafted MCP config objects with embedded command injection payloads. When a victim opens this malicious content, the MCP Manager processes the configuration objects without proper validation, executing the injected commands and escaping the sandbox environment.
The vulnerability allows attackers to chain command injection with sandbox escape, escalating from a sandboxed context to arbitrary code execution at medium integrity. For detailed technical information, refer to the Zero Day Initiative Advisory ZDI-26-023.
Detection Methods for CVE-2026-0757
Indicators of Compromise
- Unexpected child processes spawned by MCP Manager for Claude Desktop
- Suspicious system calls originating from the MCP Manager process
- Abnormal network connections initiated from within the application sandbox
- Evidence of command shell invocations from MCP Manager processes
Detection Strategies
- Monitor process creation events for unexpected child processes spawned by MCP Manager
- Implement application-level logging for MCP config object processing operations
- Deploy endpoint detection rules targeting command injection patterns in MCP Manager contexts
- Use behavioral analysis to detect sandbox escape attempts
Monitoring Recommendations
- Enable verbose logging for MCP Manager for Claude Desktop
- Monitor for suspicious command-line arguments passed to system functions
- Track network activity originating from the application for signs of post-exploitation
- Review system audit logs for unauthorized process spawning or privilege changes
How to Mitigate CVE-2026-0757
Immediate Actions Required
- Restrict access to MCP Manager for Claude Desktop until a patch is available
- Block known malicious URLs and file types associated with exploitation attempts
- Educate users about the risks of opening untrusted files or visiting suspicious websites
- Consider disabling or limiting the execute-command functionality if possible
Patch Information
As of the last NVD update on 2026-01-26, organizations should monitor for vendor security updates. Refer to the Zero Day Initiative Advisory ZDI-26-023 for the latest remediation guidance and patch availability information from the vendor.
Workarounds
- Implement network-level controls to restrict access to untrusted content
- Use application allowlisting to control what processes can be spawned
- Deploy web filtering solutions to block access to known malicious sites
- Consider running MCP Manager in a more restrictive environment until patches are applied
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
