High exploit reference

CVE-2026-4137 — Incomplete Fix for CVE-2025-10279: Insecure Temporary Directory Permissions in mlflow/mlflow

In mlflow/mlflow versions prior to 3.11.0, the `get_or_create_nfs_tmp_dir()` function in `mlflow/utils/file_utils.py` creates temporary directories with world-writable permissions (0o777), and the `_create_model_downloading_tmp_dir()` function in `mlflow/pyfunc/__init__.py` creates directories with group-writable permissions (0o770). These insecure permissions allow local attackers to tamper with model artifacts, such as cloudpickle-serialized Python objects, and achieve arbitrary code execution when the tampered artifacts are deserialized via `cloudpickle.load()`. This vulnerability is particularly critical in environments with shared NFS mounts, such as Databricks, where NFS is enabled by default. The issue is a continuation of the vulnerability class addressed in CVE-2025-10279, which was only partially fixed.

Published May 18, 2026 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: @huntr_ai

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+1
Technical severity (high)+6
CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.16%

ahead of 5% of scored CVEs · Oct 14, 2026

Affects

Lfprojects

Mlflow

CVSS base

7.8

High · 3 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Proof of concept

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

Documented patch — github.com (NIST National Vulnerability Database)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Lfprojects Mlflow, Mlflow Mlflow).
Apply the fixed version or the patch documented under Remediation.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Lfprojects	Mlflow	< 3.11.0	Vulnerable	NIST National Vulnerability Database
Mlflow	Mlflow	< 3.11.0	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
7.8	CVSS 3.1	High	1.8	5.9	nvd@nist.gov via NIST National Vulnerability Database
7.0	CVSS 3.0	High	1.0	5.9	security@huntr.dev via NIST National Vulnerability Database
7.0	CVSS 3.0	High	—	—	@huntr_ai via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 7.8 (NVD (NIST)) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-378

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.16%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.

endpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · mlflow/mlflow/mlflow
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Fix documented
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 7.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 13, 2026 · NIST National Vulnerability Database
CVE published
May 18, 2026 · @huntr_ai

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

2 on the record

github.com/mlflow/mlflow/commit/1dcbb0c2fbd1f446c328830e601ca13a28219b8a
Patch, NIST National Vulnerability Database
huntr.com/bounties/648dc30b-76c7-4433-86b8-f43d926fd8d6
Exploit, Third Party Advisory, NIST National Vulnerability Database

Elsewhere on this site

Lfprojects
every CVE for this vendor

CWE-378
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-64849 MLflow Server-Side Request Forgery Vulnerability KEV Aug 17, 2026
High CVE-2026-8147 Authorization Bypass in mlflow/mlflow Jul 2, 2026
High CVE-2026-13484 MLflow Experiment-scoped Label Schema CRUD API authorization Jun 28, 2026
Low CVE-2026-10803 MLflow Dataset Digest Computation digest_utils.py mlflow.data.digest_utils weak hash Jun 4, 2026
High CVE-2026-4035 Environment Variable Resolution Vulnerability in mlflow/mlflow Jun 3, 2026
Medium CVE-2026-3198 Improper Access Control in mlflow/mlflow Jun 2, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-4137 is "Incomplete Fix for CVE-2025-10279: Insecure Temporary Directory Permissions in mlflow/mlflow", rated High. It affects Mlflow (Lfprojects); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.16% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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