CVE-2026-2651: Auth Bypass (CVSS 9)

Description

A vulnerability in MLflow versions <=3.10.1.dev0 allows unauthorized access to multipart upload (MPU) endpoints when the `--serve-artifacts` mode is enabled. The authorization logic does not enforce resource-level permission checks for `/mlflow-artifacts/mpu/*` endpoints, enabling attackers to overwrite artifacts belonging to other users. This can lead to unauthorized cross-user writes, model supply chain poisoning, and arbitrary code execution when compromised models are loaded. The issue is resolved in version 3.10.0.

Is your site exposed to CVE-2026-2651?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.0

CRITICAL

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

EPSS — Exploit Prediction

0.0038

Probability of exploitation

0.30%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-862 Missing Authorization

References

Other References

https://github.com/mlflow/mlflow/commit/d7290811d8f3c95366d80109424edc1fb1ad966f https://huntr.com/bounties/65beb119-d3e0-4e03-af2f-fa98f78f83dc https://huntr.com/bounties/65beb119-d3e0-4e03-af2f-fa98f78f83dc

Frequently Asked Questions

What is CVE-2026-2651? +

A vulnerability in MLflow versions <=3.10.1.dev0 allows unauthorized access to multipart upload (MPU) endpoints when the `--serve-artifacts` mode is enabled. The authorization logic does not enforce resource-level permission checks for `/mlflow-artifacts/mpu/*` endpoints, enabling attackers to overwrite artifacts belonging to other users. This can lead to unauthorized cross-user writes, model supply chain poisoning, and arbitrary code execution when compromised models are loaded. The issue is resolved in version 3.10.0. It has a CVSS v3.1 base score of 9.0 (CRITICAL).

How severe is CVE-2026-2651? +

CVE-2026-2651 has a CVSS v3.1 score of 9.0 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0038, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-2651? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-40570

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, the `load_customer_info` action in `POST /conversation/ajax` …

CVE-2026-48127

Frappe is a full-stack web application framework. Prior to 16.20.0 and 15.110.0, users without write access could attach files to …

CVE-2026-42317

GLPI is a free asset and IT management software package. Starting in version 0.78 and prior to versions 10.0.25 and …

CVE-2026-4881

In affected versions of Octopus Server, permissions were not checked correctly resulting in any authenticated user being able to make …

CVE-2026-40543

SOPlanning does not enforce authorization for backup functionalities. An unauthenticated attacker can directly query backup-related endpoints and retrieve backup archives …

CVE-2026-10831

A denial-of-service vulnerability exists in NPort devices because of improper access control on the command port. The command interface does …

CVE-2026-2651