CyberSecBulletin
CVE-2026-2635NVD status: Deferred

MLflow: Use of Default Password

CVE-2026-2635 is a high-severity use of default password vulnerability in MLflow, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected MLflow versions: 3.4.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.08% chance of exploitation within 30 days, higher than 66% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of MLflow you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
MLflowMLflow3.4.0Not stated
Red HatRed Hat OpenShift AI (RHOAI)Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
LowSome restricted data can be read.
Integrity
LowLimited modification of data is possible.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L. Scored by CNA.

Scoring systemScoreSeverityScored by
CVSS 3.17.3HighCNA
CVSS 3.09.8CriticalCNA (trendmicro.com)

Official description

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 basic_auth.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. Was ZDI-CAN-28256.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Default Password

The product uses default passwords for potentially critical functionality.

How developers prevent this class of flaw

  • Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations.
  • Ensure that product documentation clearly emphasizes the presence of default passwords and provides steps for the administrator to change them.
  • Force the administrator to change the credential upon installation.

More Use of Default Password vulnerabilities (CWE-1393)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Patches and release notes

Other vulnerabilities in MLflow

All MLflow vulnerabilities

Recent Use of Default Password vulnerabilities

Spotted an error? Tell us.