What’s Vulnerable › Vulnerabilities

CVE-2026-49357: Streamable HTTP mode exposes LINE Desktop read/send tools without MCP authentication

• Severity: high (CVSS 8.8 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-19 · updated 2026-10-26
• Weakness: CWE-306

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.

Affected products

• dtwang line-desktop-mcp: before 1.1.2

References

• https://github.com/dtwang/line-desktop-mcp/commit/680617894981ea93f8f6ceb51ecde7519754d501
• https://github.com/dtwang/line-desktop-mcp/security/advisories/GHSA-4hf8-5mjm-rfgq

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