CVE-2026-18991 in NanoClaw
Summary
by MITRE • 08/06/2026
A security vulnerability has been detected in nanocoai NanoClaw up to 2.0.64. This affects an unknown part of the file container/agent-runner/src/mcp-tools/core.ts of the component send_file. Such manipulation leads to path traversal. The attack can be executed remotely. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.
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Analysis
by VulDB Data Team • 08/06/2026
This vulnerability in nanocoai NanoClaw version 2.0.64 represents a critical path traversal flaw that affects the send_file component within the container/agent-runner/src/mcp-tools/core.ts file. The issue stems from inadequate input validation and sanitization mechanisms that fail to properly handle malicious file paths, allowing attackers to manipulate directory traversal sequences and access unauthorized files or directories on the system. Path traversal vulnerabilities fall under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, making this a well-documented and dangerous security weakness. The remote exploitability of this vulnerability means that attackers can leverage it from external networks without requiring local system access, significantly expanding the attack surface and potential impact.
The technical implementation flaw manifests in how the send_file function processes file path inputs within the core.ts module, where user-supplied data is not adequately filtered or validated before being used in file system operations. This creates a direct pathway for malicious actors to traverse directory structures beyond intended boundaries, potentially accessing sensitive configuration files, system binaries, or other restricted resources. The vulnerability's exploitation requires careful crafting of path traversal sequences such as ../ or ..\ that bypass normal access controls and allow unauthorized file system navigation. Given that the exploit has been publicly disclosed and is actively available for use, this creates an immediate risk to systems running affected versions of NanoClaw.
The operational impact of this vulnerability extends beyond simple unauthorized file access, as it could enable attackers to escalate privileges, execute arbitrary code, or exfiltrate sensitive data from compromised systems. Attackers might leverage the path traversal capability to read system configuration files that contain database credentials, API keys, or other sensitive information. The lack of response from the project maintainers since early issue reporting creates an urgent security concern, as organizations using NanoClaw remain exposed to potential exploitation while waiting for official patches. This delay in remediation increases the window of opportunity for threat actors who may already have access to working exploits.
Organizations should implement immediate mitigations including restricting network access to affected systems, deploying network segmentation controls, and monitoring for suspicious file system access patterns that might indicate path traversal attempts. The recommended approach involves applying the latest available security patches from nanocoai as soon as they become available, while also implementing input validation mechanisms at multiple layers of the application architecture. Security teams should consider adopting runtime protection solutions that can detect and block malicious path traversal attempts in real-time, aligning with ATT&CK technique T1059.007 for command and scripting interpreter usage. Additionally, organizations should conduct comprehensive vulnerability assessments to identify any other components that might be susceptible to similar path traversal issues within their nanocoai deployment environments.