CVE-2026-49257 Elastic Security · Elastic

Detect CVE-2026-49257: mcp-pinot Unauthenticated Tool Invocation via Default oauth_enabled=False in Elastic Security

Detects exploitation of CVE-2026-49257, a critical authentication bypass in mcp-pinot-server (<=3.0.1). The server defaults to oauth_enabled=False and binds to 0.0.0.0, allowing any network-adjacent or internet-facing attacker to invoke MCP tools without authentication. CVSS 10.0 with public PoC available.

MITRE ATT&CK

Tactic
Initial Access Privilege Escalation Exfiltration

Elastic Detection Query

Elastic Security (Elastic)
eql 
network where event.type == "connection_attempted"
  and destination.port in (8000, 8080, 8443, 9000, 3000)
  and (
    process.name like~ "python*" or
    process.name like~ "uvicorn*" or
    process.command_line like~ "*mcp*pinot*" or
    process.command_line like~ "*mcp_pinot*"
  )
  and not source.ip == "127.0.0.1"
  and not source.ip like "10.*"
  and http.request.headers.authorization == null
critical severity medium confidence

EQL correlation rule to identify external network connections to mcp-pinot server processes where HTTP requests lack Authorization headers, suggesting CVE-2026-49257 exploitation from external sources.

Data Sources

Elastic EndpointNetwork packet captureElastic APM

Required Tables

logs-endpoint.events.network-*logs-apm.access-*

False Positives & Tuning

  • Internal localhost connections that do not require auth headers
  • RFC 1918 addresses on trusted internal segments if internal auth is bypassed at the network layer
  • API gateways terminating TLS and not forwarding Authorization headers downstream
  • CI/CD pipeline automated tests hitting non-production endpoints

Other platforms for CVE-2026-49257

Microsoft Sentinel (KQL) Splunk (SPL) IBM QRadar (QRadar) Sumo Logic CSE (Sumo) Google Chronicle (YARA-L) CrowdStrike LogScale (LogScale) All platforms (combined) →

Testing Methodology

Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.

  1. Test 1Verify Unauthenticated MCP Tool Listing

    Expected signal: HTTP 200 response with JSON list of available Pinot MCP tools returned without any authentication challenge; no 401 or 403 status code issued.

  2. Test 2Unauthenticated Pinot Query Execution via MCP Tool

    Expected signal: Pinot query execution log entry showing query 'SELECT * FROM myTable LIMIT 10' from MCP server without session token; HTTP 200 from mcp-pinot-server with query results in response body.

  3. Test 3External Network Exploitation Simulation

    Expected signal: Inbound TCP connection from external IP to port 8000; HTTP POST to /tools/list and /tools/call with source IP from outside trusted ranges; no TLS client certificate or Authorization header present.

  4. Test 4Confirm Vulnerable Package Version in Environment

    Expected signal: Command execution events showing pip, find, and ps commands with mcp-pinot arguments; output revealing package version <= 3.0.1 and running process details.

Last updated: 2026-06-27 Research depth: standard
References (6)

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