MLflow: LogInputs endpoint bypasses per-run UPDATE authorization in basic-auth

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS

• CVE-2026-69146: 0.39% estimated exploitation activity in the next 30 days; percentile 33.02 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary When MLflow is deployed with the built-in basic-auth plugin (--app-name basic-auth), any authenticated user can inject arbitrary dataset records into another user's run by calling POST /api/2.0/mlflow/runs/log-inputs. The LogInputs proto handler is absent from the BEFOREREQUESTHANDLERS map in mlflow/server/auth/init.py, so the before-request hook skips authorization entirely and the request succeeds. Standard write endpoints on the same run -- such as POST /api/2.0/mlflow/runs/log-metric -- correctly return HTTP 403. Details MLflow's basic-auth app gates every HTTP handler through a before-request hook (beforerequest) that looks up the relevant permission validator in BEFOREREQUESTVALIDATORS. Validators are built from the BEFOREREQUESTHANDLERS dictionary, which maps each protobuf request class to a callable. When a class is absent from the dict (or mapped to None), getbeforerequesthandler returns None, and the resulting entry in BEFOREREQUESTVALIDATORS is (path, method):…

Published by the source

17 Aug 2026, 21:59 UTC

Last modified by the source

17 Aug 2026, 21:59 UTC

Source last checked

26 Oct 2026, 13:01 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-3p64-6gvh-82v5

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# Patch Next advisory brief: CVE-2026-69146

Advisory: MLflow: LogInputs endpoint bypasses per-run UPDATE authorization in basic-auth
IDs: CVE-2026-69146, GHSA-3p64-6gvh-82v5
Record: https://patchnext.com/advisories/cve-2026-69146 (revision 1, source checked 26 Oct 2026, 13:01 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mlflow 3.15.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm mlflow: affected < 3.15.0; fixed in 3.15.0

## Suggested inspection (read-only)
- `npm ls mlflow --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on mlflow.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-3p64-6gvh-82v5 (GitHub-reviewed advisory GHSA-3p64-6gvh-82v5 lists affected ranges: npm mlflow >=0 <3.15.0)

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