CVE-2026-90809 in nanobot
Summary
by MITRE • 09/14/2026
A vulnerability was identified in HKUDS nanobot up to 0.2.1. The affected element is the function ExecTool._guard_command/ExecTool._spawn of the file nanobot/agent/tools/shell.py of the component ExecTool. Such manipulation leads to argument injection. It is possible to launch the attack remotely. The name of the patch is af582246f141311d574551b7571a517bcc3df750. It is best practice to apply a patch to resolve this issue.
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Analysis
by VulDB Data Team • 09/14/2026
The vulnerability identified in HKUDS nanobot versions up to 0.2.1 represents a critical security flaw within the ExecTool component, specifically affecting the internal functions _guard_command and _spawn located in the shell.py module of the agent tools directory. This architectural weakness allows for argument injection attacks, where an attacker can manipulate command-line arguments passed to system utilities or scripts executed by the nanobot agent. The root cause lies in insufficient validation and sanitization of input parameters before they are processed by the underlying operating system commands. When the ExecTool component receives a request to execute a tool or shell command, it fails to properly escape special characters or enforce strict allow-lists for acceptable arguments. This lack of rigorous input handling creates an opening for malicious actors to inject additional commands or modify existing ones, effectively bypassing intended execution constraints and altering the behavior of the agent in unintended ways.
From an operational perspective, this vulnerability is particularly severe because it can be exploited remotely. The ability to launch attacks over a network means that any system running the affected version of HKUDS nanobot is exposed to potential compromise without requiring physical access or local user interaction. An attacker who gains network connectivity to the target could craft specific payloads designed to exploit the argument injection flaw, potentially leading to unauthorized command execution with the privileges of the process running the nanobot agent. This scenario aligns closely with Common Weakness Enumeration (CWE) category CWE-78, which describes Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The remote exploitability further elevates the risk profile, placing this vulnerability within the context of ATT&CK technique T1059, specifically sub-techniques related to command and script interpretation such as PowerShell or Bash scripting, depending on the target environment's operating system.
The implications of a successful exploitation are significant for organizational security posture. If an attacker successfully injects arguments into the ExecTool functions, they may achieve arbitrary code execution, data exfiltration, lateral movement within the network, or complete control over the compromised host. Since nanobot agents often operate with elevated privileges to perform system management tasks, this privilege escalation potential makes the vulnerability a high-severity threat. The patch identified by commit hash af582246f141311d574551b7571a517bcc3df750 addresses these issues by implementing stricter input validation mechanisms and ensuring that all command arguments are properly escaped or validated against a predefined set of safe parameters. This patch effectively closes the attack vector by preventing malicious characters from influencing the execution context of system commands.
To mitigate this vulnerability, it is imperative to apply the provided patch immediately across all systems running HKUDS nanobot versions 0.2.1 and earlier. Organizations should verify their inventory for affected instances and prioritize deployment during maintenance windows to minimize operational disruption. In addition to applying the software update, security teams should implement network-level controls such as firewalls or intrusion detection system rules that monitor for anomalous command execution patterns originating from nanobot agents. Regular auditing of agent logs can also help detect any attempted exploitation activities before they result in successful compromise. Long-term remediation strategies should include integrating static application security testing into the development pipeline to catch similar input validation flaws early, and conducting periodic penetration tests focused on remote code execution vectors to ensure robust defense against evolving threat landscapes.