CVE-2026-0545: mlflow FastAPI Job Endpoints Under `/ajax-api/3.0/jobs/*` Vulnerability

CRITICAL
Advisory Identifier: GHSA-7qhf-v65m-g5f3
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CVSS 9.1
CWE-306
Published
Advisory Summary

CVE-2026-0545 is a CRITICAL (CVSS 9.1) fastapi job endpoints under `/ajax-api/3.0/jobs/*` vulnerability (CWE-306: Missing Authentication for Critical Function) affecting mlflow libraries in the PyPI ecosystem. The issue involves fastapi job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization. Remediation is available in the latest vendor maintenance releases.

CVE-2026-0545 at a Glance

CVE Identifier CVE-2026-0545
GHSA Identifier GHSA-7qhf-v65m-g5f3
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-306: Missing Authentication for Critical Function
Affected Product mlflow
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2026-0545

To remediate this vulnerability, upgrade all affected mlflow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

mlflow fixed: Latest secure release 
pip install mlflow>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show mlflow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-0545, inspect your installed packages using pip:

pip show mlflow

Analyze the terminal output to locate any version of mlflow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show mlflow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-306: Missing Authentication for Critical Function, where the product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. In mlflow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

In mlflow/mlflow, the FastAPI job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization when the `basic-auth` app is enabled. This vulnerability affects the latest version of the repository. If job execution is enabled (`MLFLOW_SERVER_ENABLE_JOB_EXECUTION=true`) and any job function is allowlisted, any network client can submit, read, search, and cancel jobs without credentials, bypassing basic-auth entirely. This can lead to unauthenticated remote code execution if allowed jobs perform privileged actions such as shell execution or filesystem changes. Even if jobs are deemed safe, this still constitutes an authentication bypass, potentially resulting in job spam, denial of service (DoS), or data exposure in job results.

CVE-2026-0545 Affected mlflow Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
mlflow
pypi/mlflow
PyPI
≤ 3.10.1

References

NVD — CVE-2026-0545 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-0545
mlflow Source Repository REPOSITORY
https://github.com/mlflow/mlflow
huntr.com/bounties/b2e5b028-9... WEB
https://huntr.com/bounties/b2e5b028-9541-4d29-8703-a76f1a3734d8

Frequently Asked Questions

What is CVE-2026-0545?
CVE-2026-0545 is a security vulnerability in mlflow involving FastAPI job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization under CWE-306: Missing Authentication for Critical Function.
Which mlflow versions are affected?
Affected versions include releases prior to current release patches across affected packages: mlflow.
What version fixes CVE-2026-0545?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is mlflow affected?
Yes, mlflow is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-0545?
CVE-2026-0545 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-0545?
CVE-2026-0545 is classified under CWE-306: Missing Authentication for Critical Function (The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.).
How can I check PyPI dependencies for CVE-2026-0545?
Run the dependency tree command: 'pip show mlflow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7qhf-v65m-g5f3",
  "modified" : "2026-04-06T23:08:07Z",
  "published" : "2026-04-03T18:31:23Z",
  "aliases" : [ "CVE-2026-0545" ],
  "summary" : "mlflow: FastAPI job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization",
  "details" : "In mlflow/mlflow, the FastAPI job endpoints under `/ajax-api/3.0/jobs/*` are not protected by authentication or authorization when the `basic-auth` app is enabled. This vulnerability affects the latest version of the repository. If job execution is enabled (`MLFLOW_SERVER_ENABLE_JOB_EXECUTION=true`) and any job function is allowlisted, any network client can submit, read, search, and cancel jobs without credentials, bypassing basic-auth entirely. This can lead to unauthenticated remote code execution if allowed jobs perform privileged actions such as shell execution or filesystem changes. Even if jobs are deemed safe, this still constitutes an authentication bypass, potentially resulting in job spam, denial of service (DoS), or data exposure in job results.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "mlflow"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "3.10.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-0545"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mlflow/mlflow"
  }, {
    "type" : "WEB",
    "url" : "https://huntr.com/bounties/b2e5b028-9541-4d29-8703-a76f1a3734d8"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-306" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-06T23:08:07Z",
    "nvd_published_at" : "2026-04-03T18:16:21Z"
  }
}