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NVD / CVE Program· CNA @huntr_ai

CVE-2026-2652: Authentication Bypass in mlflow/mlflow

Noroxi assessment

Priority: Plan (action score 40/100)

  • A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
  • Public proof-of-concept code exists (Exploit-DB / GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 20.7% (FIRST EPSS); higher than 97.5% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: mlflow mlflow/mlflow 3.10.0.

Add it to your regular patch cycle. Upgrade to mlflow mlflow/mlflow 3.10.0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A vulnerability in mlflow/mlflow versions 3.9.0 and earlier allows unauthenticated access to certain FastAPI routes when the server is started with authentication enabled (`--app-name basic-auth`) and served via uvicorn (ASGI). The FastAPI permission middleware only enforces authentication on `/gateway/` routes, leaving other routes such as the Job API (`/ajax-api/3.0/jobs/*`) and the OpenTelemetry trace ingestion API (`/v1/traces`) unprotected. This allows unauthenticated remote attackers to submit jobs, read job results, cancel running jobs, and inject arbitrary trace data into experiments. The issue arises from an architectural mismatch between Flask and FastAPI authentication mechanisms, where the `_find_fastapi_validator()` function fails to handle non-`/gateway/` paths, resulting in a complete authentication bypass. This vulnerability is fixed in version 3.10.0.

HighCVSS 8.6 · v3.0—Proof of concept Fix available
Published
May 14, 2026
Updated
Jun 17, 2026
EPSS
20.7% · 97th percentile

Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
6 / 30 · 20.7%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · @huntr_ai
8.6
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-2652

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
lfprojectsmlflow

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • lfprojects mlflowbefore 3.10.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (@huntr_ai). Independent of NVD's CPE analysis and usually ahead of it.

  • mlflow mlflow/mlflow

    • unspecified and later · before 3.10.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPImlflowbefore 3.11.03.11.0
PyPImlflowbefore 3.10.03.10.0

Same product

lfprojects: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-64849MLflow: Unauthenticated full-read SSRF in webhook delivery: _validate_webhook_url bypassed via unvalidated HTTP redirects (and DNS rebinding)KEV
    70This week
  • CVE-2023-3765Absolute Path Traversal in mlflow/mlflow
    60This week
  • CVE-2023-1177Path Traversal: '\..\filename' in mlflow/mlflow
    60This week

Published before and after this one in the same product

  • ← EarlierCVE-2026-2393May 11, 2026 · Server-Side Request Forgery (SSRF) in mlflow/mlflow
    28Monitor
  • ← EarlierCVE-2026-2614May 11, 2026 · Arbitrary File Read via Prompt Tag Source Validation Bypass in mlflow/mlflow
    31Monitor
  • Later →CVE-2026-4137May 18, 2026 · Incomplete Fix for CVE-2025-10279: Insecure Temporary Directory Permissions in mlflow/mlflow
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
mlflow mlflow/mlflow3.10.0 · descriptionVendor (CNA)
PyPI:mlflow3.10.0Package registry (OSV)
PyPI:mlflow3.11.0Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Nuclei detection template ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Nuclei detection templateNuclei template CVE-2026-2652 —

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-265111 days apartMissing Authorization Validation in mlflow/mlflow
    36Monitor
  • CVE-2026-41374 days apartIncomplete Fix for CVE-2025-10279: Insecure Temporary Directory Permissions in mlflow/mlflow
    31Monitor
  • CVE-2026-059644 days apartCommand Injection in mlflow/mlflow
    31Monitor
  • CVE-2026-23933 days apartServer-Side Request Forgery (SSRF) in mlflow/mlflow
    28Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
high · data or configuration can be modified
Availability
low · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
High
Availability impact
Low

Weakness class (CWE)

CWE-305 · Authentication Bypass by Primary Weakness

CVSS vector

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records