Cyber Resilience

CVE-2025-49596

Critical

Published: 13 June 2025

Published
13 June 2025
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 9.4 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0222 84.8th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-49596 is a critical-severity Missing Authentication for Critical Function (CWE-306) vulnerability in Thenewstack (inferred from references). Its CVSS base score is 9.4 (Critical).

Operationally, ranked in the top 15.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as AI Agent Protocols and Integrations; in the Protocol-Specific Risks risk domain.

Deeper analysis

The MCP Inspector is a developer tool used for testing and debugging MCP servers. Versions below 0.14.1 contain a remote code execution vulnerability stemming from missing authentication between the Inspector client and proxy, which permits unauthenticated requests to execute MCP commands over stdio. The flaw is tracked as CWE-306 and carries a CVSS 4.0 score of 9.4.

An attacker with network access can exploit the issue by sending crafted requests to the unauthenticated proxy interface, resulting in arbitrary command execution with high impact to confidentiality, integrity, and availability, plus scope change. No user interaction or privileges are required beyond the ability to reach the exposed component.

Public advisories and the associated GitHub security advisory direct users to upgrade immediately to version 0.14.1 or later; a patch commit addressing the authentication gap is referenced in the repository.

The vulnerability pertains to the Model Context Protocol ecosystem used in AI tooling, with coverage highlighting risks around untrusted code execution in such environments. EPSS rose from a low baseline to a recorded peak of 0.0412, indicating emerging exploitation interest after disclosure.

EU & UK References

Vulnerability details

The MCP inspector is a developer tool for testing and debugging MCP servers. Versions of MCP Inspector below 0.14.1 are vulnerable to remote code execution due to lack of authentication between the Inspector client and proxy, allowing unauthenticated requests to…

more

launch MCP commands over stdio. Users should immediately upgrade to version 0.14.1 or later to address these vulnerabilities.

CWE(s)

AI Security AnalysisAI

AI Category
AI Agent Protocols and Integrations
Risk Domain
Protocol-Specific Risks
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: mcp

Related Threats

Affected Assets

Thenewstack
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-306

Requires established identification and authentication to unlock, mitigating missing authentication for continued system access.

addresses: CWE-306

Requiring identification and rationale for actions allowed without authentication ensures critical functions are not left unprotected by forcing review of authentication requirements.

addresses: CWE-306

Authorizing mobile device connections to organizational systems ensures authentication is performed for this critical access function.

addresses: CWE-306

Guarantees critical functions are protected by mandatory invocation of the access control mechanism.

addresses: CWE-306

Auditing sessions makes it possible to detect access to critical functions without required authentication.

addresses: CWE-306

The assessment process confirms authentication is present and effective for critical functions, preventing exploitation from missing authentication.

addresses: CWE-306

Certification assesses that critical functions have required authentication controls in place.

addresses: CWE-306

Disabling non-essential functions and services eliminates the need to secure them, reducing exposure from missing authentication on unnecessary components.

References