Stored XSS via unsafe YAML parsing in MLflow
Summary
| CVE | CVE-2026-33865 |
|---|---|
| State | PUBLISHED |
| Assigner | CERT-PL |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-07 13:16:46 UTC |
| Updated | 2026-04-09 14:16:30 UTC |
| Description | MLflow is vulnerable to Stored Cross-Site Scripting (XSS) caused by unsafe parsing of YAML-based MLmodel artifacts in its web interface. An authenticated attacker can upload a malicious MLmodel file containing a payload that executes when another user views the artifact in the UI. This allows actions such as session hijacking or performing operations on behalf of the victim. This issue affects MLflow version through 3.10.1 |
Risk And Classification
Primary CVSS: v4.0 5.1 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.000570000 probability, percentile 0.177510000 (date 2026-04-13)
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 5.1 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 5.1 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
LowUser Interaction
PassiveConfidentiality
NoneIntegrity
LowAvailability
NoneSub Conf.
LowSub Integrity
LowSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/mlflow/mlflow/pull/21435 | [email protected] | github.com | |
| afine.com/blogs/attacking-mlflow-how-ml-artifacts-become-attack-vectors | [email protected] | afine.com | |
| cert.pl/en/posts/2026/04/CVE-2026-33865 | [email protected] | cert.pl | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Sławomir Zakrzewski (AFINE) (en)
There are currently no legacy QID mappings associated with this CVE.