PYSEC-2026-2660

MLflow authenticated users can enumerate any registered model versions due to lack of per-model permissions checks

Description

In mlflow/mlflow versions up to 3.9.0, the `SearchModelVersions` REST API endpoint and the `mlflowSearchModelVersions` GraphQL query lack proper per-model authorization checks when basic authentication is enabled. This allows any authenticated user to enumerate all model versions across all registered models, regardless of their permission level. The issue arises due to the absence of `SearchModelVersions` in the `BEFORE_REQUEST_VALIDATORS` and `AFTER_REQUEST_HANDLERS` for the REST API, and its omission from `GraphQLAuthorizationMiddleware.PROTECTED_FIELDS` for GraphQL. This vulnerability can expose sensitive information such as model names, version descriptions, source URIs, tags, and other metadata, potentially revealing proprietary or confidential details in multi-tenant environments. The issue is resolved in version 3.10.0.

Affected packages

References

• https://nvd.nist.gov/vuln/detail/CVE-2026-2734 ADVISORY
• https://github.com/mlflow/mlflow/commit/6989066af33fdcb03588fd71a1a67f8fc5ef12c9 WEB
• https://github.com/mlflow/mlflow PACKAGE
• https://huntr.com/bounties/d632f783-b2c7-4a3b-af5e-1d693e841c08 WEB
• https://pypi.org/project/mlflow PACKAGE
• https://github.com/advisories/GHSA-w5xq-c4pf-ghq7 ADVISORY

Sources