CVE-2025-58444Network attack vector

Command execution via unvalidated OAuth redirect URL

Published Sep 8, 2025 · Updated Sep 9, 2025

Cross-site scripting in Model Context Protocol MCP Inspector before 0.16.6 allows remote attackers to execute commands via a malicious OAuth redirect URL. AuthDebugger and OAuthFlowProgress use an unvalidated server-supplied authorization URL in window.location.href, window.open, and an anchor href, permitting javascript: or data: URLs to execute in the Inspector context. Exploitation requires a user to connect the Inspector to an untrusted MCP server and follow its OAuth flow; injected script can invoke the local proxy and run commands on the developer host.

CVSS severity8.6
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Model Context Protocol MCP Inspector before 0.16.6 allows remote attackers to execute commands via a malicious OAuth redirect URL. AuthDebugger and OAuthFlowProgress use an unvalidated server-supplied authorization URL in window.location.href, window.open, and an anchor href, permitting javascript: or data: URLs to execute in the Inspector context. Exploitation requires a user to connect the Inspector to an untrusted MCP server and follow its OAuth flow; injected script can invoke the local proxy and run commands on the developer host.

The record

CVE
CVE-2025-58444
Published
Sep 8, 2025
Updated
Sep 9, 2025
Vendor
Model Context Protocol
Product
MCP Inspector
Classifications
CWE-84, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 0.16.6

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Model Context Protocol · MCP Inspectorversion=< 0.16.6

Published CVSS scores

8.6GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/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-84Improper Neutralization of Encoded URI Schemes in a Web Page
T1203Exploitation for Client Execution

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

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Your stack

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