Description
The Model Context Protocol has a security warning advising servers to validate the "Origin" header on all incoming connections to prevent DNS rebinding attacks. Prior to the v0.25.0 release, users had no way to validate the origin's host. In v0.25.0, a new "--allowed-hosts" flag was introduced alongside the existing "--allowed-origins" flag, enabling users to specify permitted hosts at server startup. Both flags default to "*", allowing users to implement strict access controls as needed without breaking existing setups. If either flag is set to "*", the server will output a startup warning about potential vulnerabilities. Documentation has also been updated to highlight these security considerations.
Published: 2026-06-13
Score: 9.4 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Mon, 15 Jun 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Sat, 13 Jun 2026 11:15:00 +0000

Type Values Removed Values Added
Title Model Context Protocol Allows DNS Rebinding Due to Origin Header Validation Failure

Sat, 13 Jun 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Google
Google mcp Toolbox For Databases
Vendors & Products Google
Google mcp Toolbox For Databases

Sat, 13 Jun 2026 09:30:00 +0000

Type Values Removed Values Added
Description The Model Context Protocol has a security warning advising servers to validate the "Origin" header on all incoming connections to prevent DNS rebinding attacks. Prior to the v0.25.0 release, users had no way to validate the origin's host. In v0.25.0, a new "--allowed-hosts" flag was introduced alongside the existing "--allowed-origins" flag, enabling users to specify permitted hosts at server startup. Both flags default to "*", allowing users to implement strict access controls as needed without breaking existing setups. If either flag is set to "*", the server will output a startup warning about potential vulnerabilities. Documentation has also been updated to highlight these security considerations.
Weaknesses CWE-346
References
Metrics cvssV4_0

{'score': 9.4, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H'}


Subscriptions

Google Mcp Toolbox For Databases
cve-icon MITRE

Status: PUBLISHED

Assigner: Google

Published:

Updated: 2026-06-15T17:21:23.894Z

Reserved: 2026-06-08T20:57:51.543Z

Link: CVE-2026-11624

cve-icon Vulnrichment

Updated: 2026-06-15T17:21:19.353Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-06-13T10:16:17.700

Modified: 2026-06-16T15:42:57.150

Link: CVE-2026-11624

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-06-13T11:00:07Z

Weaknesses