# CVE-2026-3198: Improper Access Control in mlflow/mlflow

> Authenticated users can bypass authorization checks to enumerate sensitive gateway secrets and model definitions in MLflow when basic-auth is enabled.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Jun 2026
- **Updated:** 2 Jun 2026
- **Also known as:** BIT-mlflow-2026-3198, GHSA-r5m9-wm49-959f, PYSEC-2026-2659

## What is CVE-2026-3198?

CVE-2026-3198 is a medium-severity missing authorization vulnerability in Lfprojects Mlflow, published on 2 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

MLflow 3.9.0 with basic-auth (`--app-name basic-auth`) fails to enforce authorization checks for multiple Gateway API 'list' endpoints. Specifically, the `BEFORE_REQUEST_HANDLERS` dictionary in `mlflow/server/auth/__init__.py` does not include entries for `ListGatewaySecretInfos`, `ListGatewayEndpoints`, and `ListGatewayModelDefinitions`. This allows any authenticated user, regardless of their assigned permissions, to enumerate all gateway secrets, endpoints, and model definitions. This vulnerability exposes sensitive information, such as API keys, endpoint configurations, and proprietary model definitions, to unauthorized users.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-3198?

4 open source packages ship an affected version, including mlflow. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mlflow` | Bitnami | From 3.9.0 | 3.10.0 |
| `mlflow` | PyPI | All versions | 3.11.0rc0 |
| `mlflow` | PyPI | All versions | 3.11.0rc0 |
| `mlflow` | PyPI | All versions | 3.11.0rc0 |

Products: Lfprojects Mlflow.

## How do I fix CVE-2026-3198?

Upgrade mlflow to a fixed version for your release line: 3.10.0 or 3.11.0rc0.

## Is CVE-2026-3198 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3198 exists.

## Other vulnerabilities in Lfprojects Mlflow

- [CVE-2026-64849](https://insights.sbomify.com/CVE-2026-64849/): MLflow Server-Side Request Forgery (critical 9.3, exploited in the wild)
- [CVE-2025-15379](https://insights.sbomify.com/CVE-2025-15379/): Command Injection in mlflow/mlflow (critical 10.0)
- [CVE-2024-0520](https://insights.sbomify.com/CVE-2024-0520/): Remote Code Execution due to Full Controlled File Write in mlflow/mlflow (critical 10.0)
- [CVE-2023-6977](https://insights.sbomify.com/CVE-2023-6977/): Path Traversal: '\..\filename' (critical 10.0)
- [CVE-2023-6709](https://insights.sbomify.com/CVE-2023-6709/): Improper Neutralization of Special Elements Used in a Template Engine in mlflow/mlflow (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3198 and fix it if it is affected.

What it is: CVE-2026-3198 is a medium-severity missing authorization vulnerability in Lfprojects Mlflow, published on 2 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3198 exists.

Affected packages and fixed versions:
- mlflow (Bitnami): affected from 3.9.0; fixed in 3.10.0
- mlflow (PyPI): affected all versions; fixed in 3.11.0rc0
- mlflow (PyPI): affected all versions; fixed in 3.11.0rc0
- mlflow (PyPI): affected all versions; fixed in 3.11.0rc0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-3198/ (Markdown: https://insights.sbomify.com/CVE-2026-3198/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3198
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3198
- OSV: https://osv.dev/vulnerability/CVE-2026-3198

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3198/
Summaries are generated and may contain mistakes; the official description above is the record.