Unauthenticated code execution via stdio proxy requests
Published Jun 13, 2025 · Updated Jul 9, 2025
Missing authentication in Model Context Protocol MCP Inspector before 0.14.1 allows remote attackers to execute commands through its proxy. The proxy's /sse endpoint accepts unauthenticated transportType, command, and args parameters and passes them to a locally spawned stdio process. Direct exploitation requires network reachability; a malicious website can instead reach the local proxy through permissive CORS after a user visits the page.
Summary
What happened
Missing authentication in Model Context Protocol MCP Inspector before 0.14.1 allows remote attackers to execute commands through its proxy. The proxy's /sse endpoint accepts unauthenticated transportType, command, and args parameters and passes them to a locally spawned stdio process. Direct exploitation requires network reachability; a malicious website can instead reach the local proxy through permissive CORS after a user visits the page.
The record
- CVE
- CVE-2025-49596
- Published
- Jun 13, 2025
- Updated
- Jul 9, 2025
- Vendor
- Model Context Protocol
- Product
- MCP Inspector
- Classifications
- CWE-306, T1189, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 13, 2025CVE publishedPublication date reported by the CVE source.
- Jul 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.
- Affected versionversion=< 0.14.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- Tenable Inspector proxy reverse-shell proof of conceptproof of concept · demonstrated
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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