CVE-2026-49357Network attack vector

Unauthenticated chat disclosure and message sending

Published Jun 19, 2026 · Updated Jun 19, 2026

Missing authentication in LINE Desktop MCP before 1.1.2 allows remote attackers to read chat history and send LINE messages. The Streamable HTTP path binds to all interfaces, creates an MCP session for each reachable POST to /mcp, and dispatches history and send-message tools without checking a bearer token or other caller credential. Exposure requires HTTP mode and network reachability to its port; successful calls act through the already logged-in LINE Desktop session.

CVSS severity8.8
High
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Missing authentication in LINE Desktop MCP before 1.1.2 allows remote attackers to read chat history and send LINE messages. The Streamable HTTP path binds to all interfaces, creates an MCP session for each reachable POST to /mcp, and dispatches history and send-message tools without checking a bearer token or other caller credential. Exposure requires HTTP mode and network reachability to its port; successful calls act through the already logged-in LINE Desktop session.

The record

CVE
CVE-2026-49357
Published
Jun 19, 2026
Updated
Jun 19, 2026
Vendor
Geoffrey Wang
Product
LINE Desktop MCP
Classifications
CWE-306, CWE-862
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Geoffrey Wang · LINE Desktop MCPversion=< 1.1.2

Published CVSS scores

8.8GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo