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CVE-2026-54449

CVE-2026-54449 · LangBot: Authenticated RCE Via MCP Configuration

This page contains facts from public vulnerability sources. Check the original advisory before updating.

LangBot is a global IM bot platform designed for LLMs. In version 4.10.7 and earlier, any authenticated user can add or change an STDIO MCP server configuration without an adequate authorization boundary. In src/langbot/pkg/provider/tools/loaders/mcp.py, StdioServerParameters accepts the configured command and arguments and starts a server-side subprocess on the LangBot server. An attacker who can sign up or obtain an account can use the Extensions MCP configuration to execute arbitrary commands with the privileges of the LangBot service, enabling data disclosure, modification, and service disruption. No fixed version is available as of this review.

CVSS 8.8 · High · EPSS 0.7%

Published
Updated

Stack: python

Affected products and versions

  • langbot

    Versions
    • <= 4.10.7: Affected

    No fix published

  • langbot PyPI

    Versions
    • 4.1.0
    • 4.1.1b1
    • 4.10.0
    • 4.10.0b1
    • 4.10.0b2
    • 4.10.0b3
    • 4.10.1
    • 4.10.2
    • 4.10.3
    • 4.10.4
    • 4.10.5
    • 4.4.1b1
    • 4.5.1
    • 4.5.2
    • 4.5.3
    • 4.5.4
    • 4.6.0
    • 4.6.0b1
    • 4.6.0b2
    • 4.6.1
    • 4.6.2
    • 4.6.3
    • 4.6.4
    • 4.6.5
    • 4.7.0
    • 4.7.1
    • 4.7.2
    • 4.8.0
    • 4.8.1
    • 4.8.2
    • 4.8.3
    • 4.8.4
    • 4.8.5
    • 4.8.6
    • 4.8.7
    • 4.9.0
    • 4.9.1
    • 4.9.2
    • 4.9.3
    • 4.9.4
    • 4.9.5
    • 4.9.6
    • 4.9.7
    Affected ranges
    • ECOSYSTEM: ≤ 4.10.5

    No fix published

Original sources

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