MLflow: Missing Authorization
CVE-2026-13484 is a high-severity missing authorization vulnerability in MLflow, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected MLflow versions: 4666cffc7912ea606d592fc38d6a75e2935f65e7. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.5% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of MLflow you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| MLflow | MLflow | 4666cffc7912ea606d592fc38d6a75e2935f65e7 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 1.3 | Low | CNA (vuldb.com) |
| CVSS 3.1 | 5.0 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 2.0 | 4.6 | Medium | CNA (vuldb.com) |
Official description
A vulnerability has been found in MLflow up to 4666cffc7912ea606d592fc38d6a75e2935f65e7. The impacted element is an unknown function of the component Experiment-scoped Label Schema CRUD API. Such manipulation leads to missing authorization. It is possible to launch the attack remotely. A high complexity level is associated with this attack. The exploitability is regarded as difficult. The exploit has been disclosed to the public and may be used. A reply to the GitHub issue explains, that "[t]he labeling schema PR has not been merged yet. The auth handlers will be added before the release."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
How developers prevent this class of flaw
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/cve/CVE-2026-13484Third Party Advisory, VDB Entry
- vuldb.com/submit/837658Third Party Advisory, VDB Entry
- vuldb.com/vuln/374481Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/mlflow/mlflow/issues/23608Issue Tracking, Third Party Advisory, Exploit
- github.com/mlflow/mlflow/issues/23608#issuecomment-4560963877Third Party Advisory, VDB Entry, Exploit, Issue Tracking
Other references
- github.com/mlflow/mlflow/Product
- vuldb.com/vuln/374481/ctiPermissions Required, VDB Entry
Other vulnerabilities in MLflow
- 8.2 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.2 High severity
Recent Missing Authorization vulnerabilities
- 9.4 Critical severity
- 7.7 High severity
- 8.8 High severity
- 8.8 High severity
- 7.1 High severity
- 8.8 High severity
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