CVE-2026-49357CWE-306CWE-862

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

High · published June 19, 2026

CVSS v4.0
8.8
EPSS
1%
Percentile
46.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.8 · HIGH
Vector
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
EPSS
0.00564 · 46.1th percentile
Weaknesses
CWE-306 · Missing Authentication for Critical Function; CWE-862 · Missing Authorization
Published
2026-06-19T13:11Z
EPSS history
Timeline
  • 19 JUN 13:11Z
    Streamable HTTP mode exposes LINE Desktop read/send tools without MCP authentication
    cvelistv5