Authorization Bypass in SearchModelVersions in mlflow/mlflow

published 2026-05-21 5 mo ago modified 2026-09-08 2 mo ago also BIT-mlflow-2026-2734 , EUVD-2026-31210 , GHSA-w5xq-c4pf-ghq7 , PYSEC-2026-2660

cvss: 6.5; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits: 0; none known

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.

Patch / fix

fixed in 3 links 1

pypi mlflow 3.10.0
bitnami mlflow 3.10.0
mlflow mlflow/mlflow 3.10.0

github.com/mlflow/mlflow@6989066 commit

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-2734 updated 2026-06-28 cvss 6.5

mlflow: mlflow: Information Disclosure via improper authorization checks

Red Hat OpenShift AI (RHOAI) rhoai/odh-mlflow-rhel9, rhoai/odh-th06-cpu-torch210-py312-rhel9, rhoai/odh-th06-rocm64-torch291-py312-rhel9, rhoai/odh-th06-cuda130-torch210-py312-rhel9, rhoai/odh-training-cuda128-torch29-py312-rhel9, rhoai/odh-pipeline-runtime-pytorch-cuda-py312-rhel9, +13 more
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 5 mo ago (2026-05-21)

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

huntr.com https://huntr.com/bounties/d632f783-b2c7-4a3b-af5e-1d693e841c08 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CNA	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
GitHub	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
OSV	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
pypi	mlflow	<3.10.0	3.10.0
bitnami	mlflow	<3.10.0	3.10.0

Affected products

mlflow mlflow/mlflow

Classification

Weakness

CWE-284 Improper Access Control

References

github.com /mlflow/mlflow/commit/6989066af33fdcb03588fd71a1a67f8fc5ef12c9
web, patch
huntr.com /bounties/d632f783-b2c7-4a3b-af5e-1d693e841c08
exploit, web, third-party-advisory, advisory
nvd.nist.gov /vuln/detail/CVE-2026-2734
advisory, web
github.com /mlflow/mlflow
package
pypi.org /project/mlflow
package
github.com /advisories/GHSA-w5xq-c4pf-ghq7
advisory

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary