CVE-2026-19243

Received Received - Intake

HKUDS Nanobot Shell Allowlist Command Injection

Publication date: 2026-08-07

Last updated on: 2026-08-07

Assigner: VulDB

Description

A security vulnerability has been detected in HKUDS nanobot up to 0.2.1. Impacted is the function ExecTool._guard_command/ExecTool._spawn of the file nanobot/agent/tools/shell.py of the component Shell Allowlist Handler. Such manipulation leads to os command injection. The attack can be executed remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 0.3.0 is recommended to address this issue. The name of the patch is 4562. It is advisable to upgrade the affected component. Multiple issues were reported to the project. They reacted with a high level of professionalism and kindness: "These five reports are variants of the same root cause: validation of shell commands containing multiple segments, wrappers, comments, or chained commands. The issue was fixed by validating every executable shell segment against the configured allowlist".

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-07

Last Modified

2026-08-07

Generated

2026-08-08

AI Q&A

2026-08-08

EPSS Evaluated

N/A

NVD

CVE-2026-19243

EUVD

EUVD-2026-54617

Affected Vendors & Products

Vendor	Product	Version / Range
hkuds	nanobot	to 0.3.0 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-77	The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
CWE-78	The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

Attack-Flow Graph

Executive Summary

This vulnerability is an OS command injection flaw in HKUDS nanobot up to version 0.2.1. It exists in the Shell Allowlist Handler component, specifically in the ExecTool._guard_command and ExecTool._spawn functions of the nanobot/agent/tools/shell.py file. The issue allows attackers to bypass command validation by chaining malicious commands after an allowlisted prefix using operators like &&, ||, ;, or |. For example, an attacker could append '&& touch /tmp/evil' to an allowlisted command like 'echo', which would then execute the malicious command.

Detection Guidance

To detect this vulnerability, check if your nanobot version is below 0.3.0. Run: nanobot --version. Inspect the shell.py file in nanobot/agent/tools/ for the ExecTool._guard_command and ExecTool._spawn functions. Look for improper command validation using re.search() on raw command strings.

Impact Analysis

If exploited, this vulnerability allows attackers to execute arbitrary commands on the system running the vulnerable nanobot instance. This could lead to file modifications, data deletion, script planting, or further host compromise. The impact depends on the privileges of the nanobot process. If the process runs with elevated privileges, the attacker could gain control over the system. The vulnerability requires an authenticated attacker who can influence an exec tool call.

Compliance Impact

This vulnerability could lead to unauthorized command execution, potentially violating GDPR by enabling unauthorized data access or modification, and HIPAA by allowing unauthorized changes to protected health information. The ability to execute arbitrary commands may result in data breaches, unauthorized data exfiltration, or system tampering, all of which are critical compliance violations.

Mitigation Strategies

Upgrade nanobot to version 0.3.0 or later immediately. If upgrading is not possible, review and update the exec.allowPatterns configuration to use exact pattern matching with re.fullmatch(). Split commands into segments and validate each segment independently against the allowlist.

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