RCE in Langbot-App Langbot
CVE-2026-54449
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.
Vulnerability class: Command Injection (OS Command Injection)
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Langbot-app Langbot — versions <= 4.10.7
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-54449?
- CVE-2026-54449 is a high-severity vulnerability in Langbot-App Langbot, classified under Command Injection. CVSS score: 8.8/10. Published 2026-08-20.
- How severe is CVE-2026-54449?
- High severity. CVSS v3 base score is 8.8 out of 10.