How severe is CVE-2026-2652?

CVE-2026-2652 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.

Is CVE-2026-2652 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-2652?

CVE-2026-2652 affects Lfprojects Mlflow. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-2652?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-2652 have an EU (EUVD) identifier?

Yes. CVE-2026-2652 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30499.

When was CVE-2026-2652 published?

CVE-2026-2652 was published on 2026-05-15 and last updated on 2026-06-17.

CVE-2026-2652

CVE-2026-2652 is a high-severity vulnerability in Lfprojects Mlflow with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-305.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 2% (71st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-30499
Weakness: CWE-305
Affected product: Lfprojects Mlflow
Published: 2026-05-15
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-2652?: 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.
How severe is CVE-2026-2652?: CVE-2026-2652 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability low.
Is CVE-2026-2652 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-2652?: CVE-2026-2652 affects Lfprojects Mlflow. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-2652?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-2652 have an EU (EUVD) identifier?: Yes. CVE-2026-2652 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-30499.
When was CVE-2026-2652 published?: CVE-2026-2652 was published on 2026-05-15 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:lfprojects:mlflow:*:*:*:*:*:*:*:*

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