CVE-2026-2652
HighExploitedPublic exploitMLflow: unauthenticated access to certain FastAPI routes
Published May 15, 2026 · Updated Sep 8, 2026 · Also known as BIT-mlflow-2026-2652, GHSA-75cm-x2w3-8mgf, PYSEC-2026-2221
Key Facts
Patch immediately- CVE-2026-2652 is a high-severity vulnerability (CVSS 8.6 v3.1) affecting Mlflow (Lfprojects), mlflow/mlflow.
- It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Aug 7, 2026. Public exploit code is available.
- EPSS estimates a 1.4% probability of exploitation in the next 30 days.
- Fixed versions are available, including Mlflow 3.10.0, Mlflow 3.11.0, Mlflow 3.16.0-r0.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
8.6
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
EPSS (30-day exploit likelihood)
1.4%
Higher than 72.1% of all scored CVEs
Exploited in the wild
Yes
2 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-2652 brief as a PDF
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Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Aug 7, 2026 | n/a | Not reported |
| CIRCL KEV | Aug 7, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
6 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| MlflowLfprojects | See advisory | 3.10.0 |
| mlflow/mlflow | >= unspecified | 3.10.0 |
Patched Releases
Mlflow
3.10.0, 3.11.0, 3.16.0-r0
mlflow/mlflow
3.10.0
Timeline
Publicly disclosed
May 15, 2026
Added to Industry KEV feed
Aug 7, 2026
Added to CIRCL KEV
Aug 7, 2026
Last updated
Sep 8, 2026
Weakness Type
- CWE-305 Authentication Bypass by Primary Weakness
- CWE-306 Missing Authentication for Critical Function
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/2xxx/CVE-2026-2652.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-2652
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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).
Affected: Mlflow (Lfprojects); mlflow/mlflow versions >= unspecified. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Aug 7, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including Mlflow 3.10.0, Mlflow 3.11.0, Mlflow 3.16.0-r0.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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