CVE-2026-18482: CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection') in Klarso GmbH neo-mjs
Description
CVE-2026-18482 is a critical OS command injection vulnerability in Klarso GmbH's neo-mjs product. The flaw exists in the FileSystemService.mjs component of the ai/mcp/server/file-system MCP server, where the functions checkSyntax() and runPlaywrightTest() unsafely interpolate user-controlled absolutePath values into shell commands. This allows an attacker to execute arbitrary operating system commands if an AI agent is tricked into invoking these functions. The vulnerability is fixed in commit 88c77fc.
CVSS v3.1
Score 9.8critical
Affected software
Klarso GmbH
neo-mjs
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Neo.mjs contains an OS command injection vulnerability (CWE-78) in the FileSystemService.mjs component, specifically in the checkSyntax() and runPlaywrightTest() functions. These functions interpolate caller-controlled absolutePath values directly into shell commands without proper neutralization, enabling arbitrary OS command execution. The vulnerability affects version 0 of neo-mjs and was addressed by a fix in commit 88c77fc.
Potential Impact
Successful exploitation allows unauthenticated remote attackers to execute arbitrary OS commands on the affected system, leading to full compromise of confidentiality, integrity, and availability. The CVSS score of 9.8 reflects the critical severity and the potential for complete system takeover without user interaction or privileges.
Mitigation Recommendations
A fix is available as indicated by the referenced commit 88c77fc. Users should apply this official patch to remediate the vulnerability. No additional vendor advisory content is provided, so check the vendor's official channels for the patch details and deployment instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- certcc
- Date Reserved
- 2026-07-31T12:46:16.513Z
- State
- PUBLISHED
Threat ID: 6a86f8a8acd9273b499fec2e
Added to database: 08/20/2026, 12:52:56 UTC
Last enriched: 09/11/2026, 00:17:21 UTC
Last updated: 10/04/2026, 16:08:36 UTC
Views: 66
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