CVE-2026-2652
Authentication Bypass in mlflow/mlflow
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Authentication Bypass in mlflow/mlflow
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
CVE-2026-2652- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-305
- Updated
- 2026-11-02
EUVDEUVD-2026-30499
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
EUVD-2026-30499- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-75cm-x2w3-8mgf
MLflow: unauthenticated access to certain FastAPI routes
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
GHSA-75cm-x2w3-8mgf- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-305
- Updated
- 2026-11-02
NVD
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
CVE-2026-2652- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-305
- Updated
- 2026-11-02
OSV
Authentication Bypass in mlflow/mlflow
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
CVE-2026-2652- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-305
- Updated
- 2026-11-02
OSVGHSA-75cm-x2w3-8mgf
MLflow: unauthenticated access to certain FastAPI routes
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
GHSA-75cm-x2w3-8mgf- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Weakness
- CWE-305
- Updated
- 2026-11-02
OSVPYSEC-2026-2221
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
PYSEC-2026-2221- CVSS 3.0
- 8.6 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L - Updated
- 2026-11-02
OSVBIT-mlflow-2026-2652 No score
Authentication Bypass in mlflow/mlflow
A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (--app-name basic-auth) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on /gateway/ routes, leaving other routes such as the Job API (/ajax-api/3.0/jobs/*) and the OpenTelemetry trace ingestion API (/v1/traces) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the _find_fastapi_validator() function fails to handle non-/gateway/ paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.
- Record
BIT-mlflow-2026-2652- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
mlflowPyPI |
before 3.11.0 | 3.11.0 |
mlflowBitnami |
before 3.10.0 | 3.10.0 |
mlflowPyPI |
before 3.11.0, plus listed versions 0.0.10.1.00.2.00.2.10.3.0 Show 45 moreShow less0.4.00.4.10.4.20.5.00.5.10.5.20.6.00.7.00.8.00.8.10.8.20.9.00.9.0.10.9.11.0.01.1.01.1.1.dev01.10.01.11.01.12.01.12.11.131.13.11.14.01.14.11.15.01.16.01.17.01.18.01.19.01.2.01.20.01.20.11.20.21.21.01.22.01.23.01.23.11.24.01.25.01.25.11.26.01.26.11.27.01.28.0 |
3.11.0 |
mlflowPyPI |
before 3.10.0, plus listed versions 0.0.10.1.00.2.00.2.10.3.0 Show 45 moreShow less0.4.00.4.10.4.20.5.00.5.10.5.20.6.00.7.00.8.00.8.10.8.20.9.00.9.0.10.9.11.0.01.1.01.1.1.dev01.10.01.11.01.12.01.12.11.131.13.11.14.01.14.11.15.01.16.01.17.01.18.01.19.01.2.01.20.01.20.11.20.21.21.01.22.01.23.01.23.11.24.01.25.01.25.11.26.01.26.11.27.01.28.0 |
3.10.0 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Nuclei | MLflow < 3.10.0 - Authentication Bypass on FastAPI Routes |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, Nuclei, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-2652 is a high vulnerability (CVSS 8.6) in Lfprojects Mlflow, published May 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 20.8%, the 97th percentile. Fixed in mlflow 3.11.0.
References
huntr.com/bounties/5aeff5f0-49c7-4180-b5cb-c9a046f16756
github.com/mlflow/mlflow/commit/bb62e773263c14e9ba4d1a82fe72d0de2442c6aa
nvd.nist.gov/vuln/detail/CVE-2026-2652
Left out here: 246 versions. The JSON record has them.