External risk intelligence

MLflow Weak Password Requirements Allow Authentication Bypass.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2025-11200

MLflow is frequently deployed as a web-based service for managing machine learning lifecycles, often including experiment tracking and model registries. These instances are commonly hosted as web applications or API endpoints that are accessible over a network, making them reachable in many standard deployment environments.

Authentication Bypass

Lfprojects Mlflow

2.21.0 and earlier

Halo Surface Signal: 4 out of 5 — likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

This vulnerability impacts MLflow, a platform used for managing machine learning lifecycles. It allows unauthenticated remote access, potentially exposing system controls. The main concern is confirming relevance and exposure within our environment.

  • Weak passwords enable unauthorized access.
  • It affects how machine learning projects are managed.
  • Confirm if MLflow is used and if it is exposed.

Attack Path

How an attacker could exploit the issue

An attacker could bypass authentication on MLflow installations by exploiting weak password requirements. This vulnerability allows remote attackers to gain unauthorized access to the system without needing any prior privileges or interaction. Once authentication is bypassed, an attacker could potentially access sensitive information or modify data within MLflow.

  • Remote attackers can reach the vulnerable component.
  • Weak password requirements are used to trigger the vulnerability.
  • Unauthenticated access to sensitive data is the primary risk.

Live Threat

Current exploitation, exposure, and threat context

Remote attackers could bypass authentication on MLflow installations when weak password requirements are exploited. This could affect system data and service behavior when supported by the advisory.

  • MLflow system data.
  • Unauthenticated network access.
  • Unauthorized system access.

Operational Fix

Recommended remediation, mitigation, and detection steps

The MLflow application owners, often data science or MLOps teams, are likely responsible for addressing this authentication bypass vulnerability. The first practical step is to identify all MLflow instances, confirm their network reachability and business criticality, and then locate the accountable owner for each instance to plan remediation.

  • Application owners must be identified.
  • Verify all MLflow instance reachability.
  • Plan and coordinate necessary updates.

Supplementary metadata

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

Frequently asked questions

What is MLflow and why is it used?

MLflow is an open-source platform managed by LF Projects designed to streamline the machine learning lifecycle. Data scientists and MLOps teams use it to track experiments, package code, and manage model registries, essentially serving as a centralized hub for tracking the progress and results of machine learning models during development and deployment.

What does CWE-521 mean for CVE-2025-11200?

CWE-521 is the weakness class for 'Weak Password Requirements.' In the context of CVE-2025-11200, this means the software's mechanisms for enforcing secure passwords are insufficient. Because these requirements are not strong enough, the system fails to effectively authenticate users, allowing an attacker to bypass the login process entirely and gain unauthorized access.

How does an attacker trigger this authentication bypass?

An attacker triggers this vulnerability by exploiting the weak password handling logic directly over the network. They do not need existing credentials, prior system privileges, or user interaction to succeed. It is important to note that this is not caused by a specific user choosing a weak password, but by the application itself failing to mandate secure password standards.

Why should I care about this vulnerability?

According to Halo Surface Signal, MLflow is commonly deployed as a web-based service with network-accessible API endpoints. If your MLflow instance is reachable over a network—especially if it is internet-facing—the risk is high because remote attackers can reach the system without authentication, potentially accessing sensitive model data or machine learning experiment history.

What are the first steps to secure my MLflow installation?

Begin by identifying all MLflow instances currently running in your environment. Once you have a list, verify their network reachability to determine which are exposed. Finally, coordinate with the MLOps or data science teams responsible for these systems to review the advisory and plan the necessary software updates to remediate the authentication flaw.

References