Executive Summary

CVE-2026-5557 is a critical vulnerability in the pi-mono Slack bot component (@mariozechner/pi-mom) version 0.58.4 and earlier. It allows any Slack workspace member to remotely execute arbitrary shell commands on the host system running the bot without any authentication or authorization.

The root causes include missing authentication checks, direct passing of Slack message content to a Large Language Model (LLM) prompt without sanitization, and the LLM having unrestricted access to execute bash commands on the host OS. The bot runs commands directly on the host with no sandboxing or filtering, enabling attackers to execute arbitrary code remotely.

Attackers can exploit this by sending specially crafted Slack messages or file attachments containing malicious commands, which the bot processes and executes, leading to full remote code execution on the host.

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Impact Analysis

This vulnerability can lead to a complete system compromise of the host running the pi-mono Slack bot. An attacker can remotely execute arbitrary shell commands with the privileges of the bot process.

• Remote Code Execution (RCE) allowing installation of malware or backdoors.
• Data exfiltration or theft of sensitive information.
• Disruption of services or destruction of data.
• Potential lateral movement within the network if the bot has network access.

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Detection Guidance

This vulnerability can be detected by monitoring Slack bot interactions for unauthorized or suspicious command executions, especially messages sent to the pi-mono Slack bot component `@mariozechner/pi-mom`.

Since the vulnerability allows remote code execution via Slack messages, detection involves checking for unusual Slack messages that trigger shell commands or unexpected processes spawned by the bot.

• Monitor Slack message logs for commands sent to the bot that include shell commands or suspicious payloads.
• On the host system, use commands like `ps aux | grep pi-mono` to identify running bot processes and check for unexpected child processes spawned by the bot.
• Use system auditing tools such as `auditd` or `sysdig` to track execution of shell commands initiated by the bot process.
• Check for files or logs created by suspicious commands, for example, by searching for recently modified files with `find / -mtime -1` or similar.

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Mitigation Strategies

Immediate mitigation steps include restricting access to the vulnerable Slack bot and preventing it from executing arbitrary commands.

• Disable or remove the pi-mono Slack bot (`@mariozechner/pi-mom`) from your Slack workspace to prevent exploitation.
• Restrict Slack workspace membership to trusted users only, as any member can exploit the vulnerability.
• Implement network-level controls to block outgoing connections or shell command executions initiated by the bot process.
• If possible, run the bot in a sandboxed or isolated environment with limited privileges to contain potential damage.
• Monitor system logs and Slack bot activity closely for signs of exploitation.

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Compliance Impact

The vulnerability allows any Slack workspace member to remotely execute arbitrary shell commands on the host running the pi-mono Slack bot, leading to complete system compromise.

Such a compromise could result in unauthorized access to sensitive data, potential data breaches, and loss of system integrity, which may violate compliance requirements under standards like GDPR and HIPAA that mandate protection of personal and sensitive information.

Because the vulnerability enables authentication bypass and remote code execution without restrictions, it undermines security controls necessary for regulatory compliance.

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