Vulnerability details

CVE-2026-54449

langbot-app LangBot

LangBot: Authenticated RCE Via MCP Configuration

CVSS 3.1

8.8High

Official description

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 scores

Score	Version	Source	Vector
8.8High	3.1	CVEProject cvelistV5 (CNA) (GitHub_M)	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`

Affected products

Vendor	Product	Versions	Source
langbot-app	LangBot	<= 4.10.7	CVEProject cvelistV5 (CNA)

References and advisories

https://github.com/langbot-app/LangBot/security/advisories/GHSA-3pvh-63gf-j9mw x_refsource_CONFIRM
https://www.ox.security/blog/mcp-supply-chain-advisory-rce-vulnerabilities-across-the-ai-ecosystem x_refsource_MISC

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Details

Published: 2026-08-20
Last updated: 2026-08-22
State: Published
Assigner (CNA): GitHub_M

Exploit prediction (EPSS)

0.72%

Probability of exploitation in 30 days

54.2%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: No
Exploitation: None
Technical impact: Total

Weaknesses (CWE)

CWE-77
Improper Neutralization of Special Elements used in a Command ('Command Injection')