ZDI-CAN-28256: ZDI-26-111: MLflow Use of Default Password Authentication Bypass Vulnerability
This vulnerability allows remote attackers to bypass authentication on affected installations of MLflow. Authentication is not required to exploit this vulnerability. The specific flaw exists within the basicauth.ini file. The file contains hard-coded default credentials. An attacker can leverage this vulnerability to bypass authentication and execute arbitrary code in the context of the administrator.
Other sources
This vulnerability allows remote attackers to bypass authentication on affected installations of MLflow. Authentication is not required to exploit this vulnerability. The ZDI has assigned a CVSS rating of 9.8. The following CVEs are assigned: CVE-2026-2635.
— ZDI
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Patch ZDI-26-111 - Configuration
Update the hard-coded default credentials in MLflow's basic_auth.ini; ensure the default username/password are removed and replaced with unique credentials.
MLflow basic_auth.ini default credentials (hard-coded default password) = remove/replace hard-coded default credentials with unique, non-default credentials - Operational
Rotate any credentials that may have used the hard-coded default values before applying the change to basic_auth.ini.
Event History
Frequently Asked Questions
What is the severity of ZDI-CAN-28256?
The severity of ZDI-CAN-28256 is critical due to the authentication bypass that allows remote attackers to exploit the vulnerability without authentication.
How do I fix ZDI-CAN-28256?
To fix ZDI-CAN-28256, ensure that the default password authentication is properly configured and not left with the default settings.
What software is affected by ZDI-CAN-28256?
ZDI-CAN-28256 affects installations of MLflow that utilize the default password configuration in the basic_auth.ini file.
Can ZDI-CAN-28256 be exploited remotely?
Yes, ZDI-CAN-28256 can be exploited remotely without requiring authentication.
What kind of attackers can exploit ZDI-CAN-28256?
Any remote attacker can exploit ZDI-CAN-28256 due to the lack of authentication requirements.