CVE-2026-49357

Streamable HTTP mode exposes LINE Desktop read/send tools without MCP authentication

State: Published
Severity: 8.8 High
Published: Jun 19, 2026
Updated: Jun 22, 2026
Reserved: May 29, 2026

Description

Line Desktop MCP is a project that, while unaffiliated with the official line-bot-mcp-server, allows users to directly operate the LINE Desktop application on Windows or Mac via MCP. `line-desktop-mcp` supports a `--http-mode` Streamable HTTP transport for use with clients such as n8n. In this mode the server binds to `0.0.0.0` and exposes the MCP `/mcp` endpoint without an MCP-layer authentication check. Prior to version 1.1.2, any network client that can reach the port can initialize a session, list tools, and call tools that read LINE Desktop chat history or send LINE messages through the already logged-in desktop application. Version 1.1.2 fixes the issue.

Scores

CVSS	Score	Vector	Source
4.0	8.8 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N	GitHub_M

Weaknesses

CWE-306 Missing Authentication for Critical Function
CWE-862 Missing Authorization

Affected Products

Product	Versions
line-desktop-mcpdtwang	< 1.1.2Affected

References

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