How severe is CVE-2026-49357?

CVE-2026-49357 has a CVSS 4.0 base score of 8.8, rated high severity.

Is CVE-2026-49357 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-49357?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-49357 have an EU (EUVD) identifier?

Yes. CVE-2026-49357 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38016.

When was CVE-2026-49357 published?

CVE-2026-49357 was published on 2026-06-19 and last updated on 2026-06-23.

CVE-2026-49357

CVE-2026-49357 is a high-severity vulnerability with a CVSS 4.0 base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

Severity: High (CVSS 4.0 base score 8.8)
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38016
Weakness: CWE-306
Published: 2026-06-19
Last modified: 2026-06-23

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.

Frequently asked questions

What is CVE-2026-49357?: 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.
How severe is CVE-2026-49357?: CVE-2026-49357 has a CVSS 4.0 base score of 8.8, rated high severity.
Is CVE-2026-49357 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-49357?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-49357 have an EU (EUVD) identifier?: Yes. CVE-2026-49357 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38016.
When was CVE-2026-49357 published?: CVE-2026-49357 was published on 2026-06-19 and last updated on 2026-06-23.

References

Other CWE-306 (Missing Authentication for Critical Function) vulnerabilities

CVE-2026-54309 — Critical (CVSS 10.0): n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, when @n8n/mcp-browser is run in HTTP…
CVE-2026-50242 — Critical (CVSS 10.0): In JetBrains Hub before 2026.1.13757, 2025.3.148033, 2025.2.148048, 2025.1.148120, 2024.3.148430, 2024.2.148429…
CVE-2026-49257 — Critical (CVSS 10.0): mcp-pinot is a Python-based Model Context Protocol (MCP) server for interacting with Apache Pinot. In versions 3.0.1…
CVE-2026-46846 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46803 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Portal product of Oracle Fusion Middleware (component: Security Framework).…
CVE-2026-46800 — Critical (CVSS 10.0): Vulnerability in the Oracle WebCenter Sites product of Oracle Fusion Middleware (component: WebCenter Sites).…

Browse all CWE-306 (Missing Authentication for Critical Function) vulnerabilities →