43/100 CVSS 7.5 🔴 CVE ANALYSISPublished: May 21, 2026

Windows-MCP: HTTP transports expose unauthenticated PowerShell control with wildcard CORS

HTTP transports expose unauthenticated PowerShell control with wildcard CORS There is an issue in the SSE and Streamable HTTP transport modes. The default stdio mode is not affected, but the documented HTTP modes expose the MCP control plane without authentication and add wildcard CORS handling around it. The same server exposes the `PowerShell` to...

7.5

CVSS Score

LOW

Threat Level

Priority /100

TBD

Exploited ITW

Monitor

CISA Status

Sources

🔵

HIGH-PRIORITY SECURITY ADVISORY — Priority Score: 43/100

CVSS 7.5 LOW. SENTINEL APEX recommends immediate patch evaluation. Intelligence from 1 confirmed source(s).

📋 Executive Summary

⚡ Analyst Assessment — SENTINEL APEX v4.0

CYBERDUDEBIVASH SENTINEL APEX has confirmed a LOW-tier threat intelligence signal for GHSA-af5b5ad240b1e34f affecting pip windows-mcp. Composite threat score: 43/100. Intelligence corroborated across 1 source(s): github_advisories. CVSS base score: 7.5. Exploitation probability assessed as HIGH based on vulnerability characteristics.

Intelligence sources: github_advisories

⚠️ Business Impact Analysis

⚠️ Remote code execution — full server takeover without authentication possible
⚠️ Authentication bypass — all access controls circumvented

🔗 Attack Chain Analysis

Step-by-step attack chain based on observed TTPs and vulnerability characteristics:

#	Phase	Attacker Action	MITRE
1	Reconnaissance	Attacker identifies exposed windows-mcp instances via Shodan, Censys, or targeted scanning	`TA0043`
2	Initial Access	Unauthenticated exploitation — no credentials required. Single HTTP request sufficient	`T1190`
3	Execution	Remote code execution achieved — attacker runs arbitrary commands on target system	`T1203`
4	Persistence	Backdoor, scheduled task, or new admin account created for persistent access	`T1053`
5	Command & Control	Attacker establishes persistent C2 channel using HTTPS or DNS tunneling	`T1071`
6	Impact / Objectives	Intellectual property theft, espionage, cryptomining, or preparation for future attack stage	`T1657`

⚠ Deep Dive Analysis

This high-severity vulnerability in pip windows-mcp (CVSS 7.5) represents a significant attack surface. SENTINEL APEX assesses exploitation to be technically feasible with moderate effort. Organizations running windows-mcp in internet-facing or privileged positions face immediate risk.

SENTINEL APEX URGENCY: ELEVATED. Score: 43/100 LOW. Patch before exploitation activity begins.

🎯 MITRE ATT&CK Mapping

Category	Mapping
Primary Tactic	Execution
Primary Technique	T1203 — Exploitation for Client Execution
Sub-Technique	T1059 — Command & Scripting Interpreter
Weakness (CWE)	CWE-306
Intel Type	🔴 CVE ANALYSIS
Source(s)	github_advisories

🔍 Detection Rules — Sigma (SIEM)

Deploy to Splunk, Elastic, Microsoft Sentinel, or QRadar. SOC Pro subscribers receive pre-compiled SIEM-native query packs updated with each pipeline run.

Sigma YAMLtitle: GHSA-af5b5ad240b1e34f Exploitation Attempt — pip windows-mcp
id: 79823e7e2777df2f-08bc
status: experimental
description: Detects exploitation of GHSA-af5b5ad240b1e34f in pip windows-mcp. Priority: LOW. Score: 43/100
author: CYBERDUDEBIVASH SENTINEL APEX v4.0 (bivash@cyberdudebivash.com)
date: 2026-05-21
references:
    - https://nvd.nist.gov/vuln/detail/GHSA-af5b5ad240b1e34f
    - https://blog.cyberdudebivash.in/
tags:
    - attack.initial_access
    - attack.t1190
logsource:
    category: webserver
detection:
    keywords:
        - 'ghsa-af5b5ad240b1e34f'
    condition: keywords
falsepositives:
    - Security scanners
level: medium

📡 Detection Rules — YARA (Endpoint)

Deploy to endpoint detection platforms. Enterprise subscribers receive tuned, FP-validated YARA rule packs.

YARArule GHSA_af5b5ad240b1e34f_Exploitation {
    meta:
        description = "Detects artifacts related to GHSA-af5b5ad240b1e34f exploitation in pip windows-mcp"
        author      = "CYBERDUDEBIVASH SENTINEL APEX v4.0"
        date        = "2026-05-21"
        severity    = "HIGH"
        cvss        = "7.5"
        priority    = "43/100"
        threat_level = "LOW"
        reference   = "https://nvd.nist.gov/vuln/detail/GHSA-af5b5ad240b1e34f"
    strings:
        $id_str  = "GHSA-af5b5ad240b1e34f" ascii nocase
        $product = "windows_mcp" ascii nocase wide
    condition:
        any of them
}

🛡️ SOC Response Playbook

1IMMEDIATE (0-1hr): Identify all instances of windows-mcp in your environment via CMDB/asset inventory
2IMMEDIATE (0-1hr): Apply vendor patch — no maintenance window exception for LOW threats
3IMMEDIATE (1-2hr): If no patch available: implement WAF rules, ACLs, or network-level compensating controls
4SHORT-TERM (2-4hr): Deploy Sigma detection rule to SIEM — validate alert generation in test environment
5SHORT-TERM (4-8hr): Review logs for exploitation indicators (anomalous windows-mcp requests, error spikes)
6SHORT-TERM (8-24hr): Hunt for post-exploitation: new admin accounts, scheduled tasks, lateral movement
7MONITOR: Subscribe to pip security advisories for patch updates
8ONGOING: Track SENTINEL APEX intelligence feed for follow-on campaigns targeting windows-mcp

📎 Intelligence References

SENTINEL INTEL BRIEF

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⚡ CYBERDUDEBIVASH SENTINEL APEX v4.0

Intelligence report generated by CYBERDUDEBIVASH SENTINEL APEX v4.0
Report ID: SENTINEL-GHSA-af5b5ad240b1e34f-2026-05-21 | Priority: 43/100 LOW | Sources: 1
© 2026 CYBERDUDEBIVASH PRIVATE LIMITED
Republication requires written attribution to CYBERDUDEBIVASH SENTINEL APEX

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