CVE-2026-49357: CWE-306: Missing Authentication for Critical Function in dtwang line-desktop-mcp
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.
AI Analysis
Technical Summary
The vulnerability arises because line-desktop-mcp's --http-mode exposes the MCP /mcp endpoint without any authentication checks, allowing any network client that can reach the port to perform sensitive operations. This missing authentication (CWE-306) on critical functions enables unauthorized access to user chat data and message sending capabilities via the already logged-in LINE Desktop application. The flaw affects all versions prior to 1.1.2, where the fix was introduced to enforce proper authentication.
Potential Impact
An attacker with network access to the exposed MCP HTTP endpoint can initialize sessions, enumerate available tools, and invoke tools that read sensitive chat history or send messages on behalf of the logged-in user without any authentication. This compromises user privacy and message integrity, potentially allowing unauthorized message sending and data leakage.
Mitigation Recommendations
Upgrade line-desktop-mcp to version 1.1.2 or later, where the authentication checks for the MCP /mcp endpoint in --http-mode are properly enforced. No other mitigations are indicated. Patch status is confirmed by the version fix information.
CVE-2026-49357: CWE-306: Missing Authentication for Critical Function in dtwang line-desktop-mcp
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.
CVSS v4.0
Score 8.8high
Affected software
pkg:github/dtwang/line-desktop-mcpRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises because line-desktop-mcp's --http-mode exposes the MCP /mcp endpoint without any authentication checks, allowing any network client that can reach the port to perform sensitive operations. This missing authentication (CWE-306) on critical functions enables unauthorized access to user chat data and message sending capabilities via the already logged-in LINE Desktop application. The flaw affects all versions prior to 1.1.2, where the fix was introduced to enforce proper authentication.
Potential Impact
An attacker with network access to the exposed MCP HTTP endpoint can initialize sessions, enumerate available tools, and invoke tools that read sensitive chat history or send messages on behalf of the logged-in user without any authentication. This compromises user privacy and message integrity, potentially allowing unauthorized message sending and data leakage.
Mitigation Recommendations
Upgrade line-desktop-mcp to version 1.1.2 or later, where the authentication checks for the MCP /mcp endpoint in --http-mode are properly enforced. No other mitigations are indicated. Patch status is confirmed by the version fix information.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-29T14:35:45.904Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a354cc5f198dc38c158777f
Added to database: 06/19/2026, 14:05:57 UTC
Last enriched: 06/26/2026, 15:16:47 UTC
Last updated: 08/03/2026, 22:37:22 UTC
Views: 86
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