CVE-2026-71211
Received Received - Intake

SSRF via Unvalidated API Base in MLflow AI Gateway

Publication date: 2026-08-05

Last updated on: 2026-08-05

Assigner: 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c

Description
MLflow's AI Gateway accepts an auth_config.api_base value when creating a gateway secret (mlflow/server/handlers.py, _create_gateway_secret) with no validation of scheme, host, or IP range; the value is stored verbatim. The gateway proxy endpoint (mlflow/server/gateway_api.py, raw_proxy) subsequently issues an HTTP request to that stored api_base plus a caller-supplied path and returns the full response body. MLflow's existing SSRF guard, _validate_webhook_url (which blocks non-global and metadata IPs), is never invoked anywhere in this gateway secret/proxy code path. The CreateGatewaySecret action additionally has no entry in the permission-validator map, so it requires only basic authentication rather than any specific scope, meaning any authenticated user — including read-only accounts — can create a secret pointing at an internal address and reach it via the proxy endpoint, potentially exposing cloud-instance IAM credentials via metadata services. This is related to CVE-2026-4035, which addresses a distinct mechanism in the same gateway-secret feature (server-side $ENV_VAR resolution inside the api_key field leaking credentials to the configured upstream); the finding here is an independent missing-validation gap in the api_base destination itself, unaffected by that fix.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-08-05
Last Modified
2026-08-05
Generated
2026-08-05
AI Q&A
2026-08-05
EPSS Evaluated
N/A
NVD
CVE-2026-71211
EUVD
EUVD-2026-53208

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
mlflow mlflow *
mlflow mlflow 3.14.0

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-918 The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This vulnerability in MLflow's AI Gateway allows authenticated users to create a gateway secret with an unvalidated api_base URL. The system stores this URL as-is and uses it to proxy HTTP requests. Since there's no validation of the scheme, host, or IP range, users can point the proxy to internal addresses. Additionally, the permission check is missing for the CreateGatewaySecret action, allowing even read-only accounts to exploit this. This could expose cloud-instance IAM credentials via metadata services.

Detection Guidance

Check for unauthorized gateway secrets pointing to internal addresses by reviewing MLflow server logs and API calls to CreateGatewaySecret. Inspect proxy endpoint traffic for requests to unexpected hosts.

Impact Analysis

An attacker with basic authentication could create a malicious gateway secret pointing to an internal service. By accessing the proxy endpoint, they could retrieve sensitive data or credentials from internal systems, potentially leading to unauthorized access, data breaches, or privilege escalation within the cloud environment.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, violating GDPR's data protection principles and HIPAA's security requirements. It may result in data breaches, unauthorized disclosure of personal or health information, and non-compliance with regulatory obligations for data security and access controls.

Mitigation Strategies

Update MLflow to the latest version that includes validation for api_base. Restrict CreateGatewaySecret permissions to require elevated scopes. Add network-level controls to block unauthorized outbound requests from the MLflow server.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-71211. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart