JunoClaw Command Bypass Vulnerability CVE-2026-43991 Poses High Risk
The National Vulnerability Database has detailed CVE-2026-43991, a high-severity vulnerability (CVSS 8.4) affecting JunoClaw, an agentic AI platform built on Juno Network. Prior to version 0.x.y-security-1, a flaw in the plugin-shell’s command-safety check allowed attackers to bypass a substring-based blocklist. This vulnerability, when combined with a companion advisory, enables unauthorized command execution on the host system.
The core issue, as described by the National Vulnerability Database, was that the command-safety check was applied to the raw command string, not the parsed first token. This allowed for adversarial argument constructions to circumvent the intended security controls. The vulnerability falls under CWE-78 (Improper Neutralization of Special Elements used in an OS Command) and CWE-184 (Incomplete Blacklist).
This is a critical flaw for any organization leveraging JunoClaw. An attacker exploiting this could gain significant control over the underlying host, leading to data compromise, system disruption, or further lateral movement. The fix is available in version 0.x.y-security-1, addressing the improper handling of command parsing.
What This Means For You
- If your organization utilizes JunoClaw, you must immediately verify that all instances are patched to version 0.x.y-security-1 or later. Prioritize patching, as an unauthenticated attacker could leverage this vulnerability for full command execution on your host systems. Audit your JunoClaw deployments for any anomalous command execution attempts pre-patch.
Related ATT&CK Techniques
🛡️ Detection Rules
2 rules · 6 SIEM formats2 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-43991 - JunoClaw Command Injection Bypass
title: CVE-2026-43991 - JunoClaw Command Injection Bypass
id: scw-2026-05-12-ai-1
status: experimental
level: critical
description: |
Detects potential command injection attempts targeting JunoClaw's plugin-shell by looking for suspicious characters often used to bypass substring-based blocklists in command arguments. This rule specifically targets the known vulnerability CVE-2026-43991 where adversarial argument constructions could lead to unauthorized command execution.
author: SCW Feed Engine (AI-generated)
date: 2026-05-12
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-43991/
tags:
- attack.execution
- attack.t1059.004
logsource:
category: process_creation
detection:
selection:
Image|startswith:
- '/opt/junoweb/bin/plugin-shell'
CommandLine|contains:
- '&&'
- ';'
- '|'
- '`'
- '$()'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-43991 | RCE | JunoClaw plugin-shell prior to version 0.x.y-security-1 |
| CVE-2026-43991 | Auth Bypass | JunoClaw plugin-shell command-safety check bypass |
| CVE-2026-43991 | Command Injection | JunoClaw plugin-shell substring-based blocklist bypass |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | May 12, 2026 at 20:16 UTC |
This content was AI-rewritten and enriched by Shimi's Cyber World based on the original source. All intellectual property rights remain with the original author.
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