MLflow's Server-Side Request Forgery Flaw Allows Remote Attackers to Use the ML Platform Server as a Proxy to Access Internal Services and Steal Credentials; CISA's September 2nd KEV Deadline Has Passed

Last refreshed2026-09-27

Status: KEV | Advisory ID: CVE-2026-64849

Key Details

CVE	CVE-2026-64849
Vulnerability Name	MLflow Server-Side Request Forgery Vulnerability
CVSS Score / Version	9.3 (Critical) / CVSS v3.1
Updated	2026-09-22
CVSS Vector	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N`
CVSS Prose	attack vector is network; attack complexity is low; privileges required is none; user interaction is none; scope is changed; confidentiality impact is high; integrity impact is low; availability impact is none.
Affected products	MLflow MLflow and lfprojects MLflow
Exploitation status	Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation.
Classified as	CWE-918 (Server-Side Request Forgery (SSRF))
KEV listing	Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-08-19.
Exploitation prediction (EPSS)	9.84% probability of exploitation in the next 30 days (95% percentile) -- FIRST.org's EPSS model.
Federal remediation deadline	2026-09-02 (CISA KEV, Binding Operational Directive).

Affected Products, Subsystems & Sectors

Vendor	Product	Affected Versions	Patch Status
MLflow	MLflow
lfprojects	MLflow

Vendor

Product

Affected Versions

Patch Status

MLflow

lfprojects

MLflow

Subsystems	General OT
Sectors	Multiple

What to Know

MLflow is an open source AI engineering platform for agents, large language models, and machine learning models. Prior to 3.15.0, the unauthenticated POST /api/2.0/mlflow/webhooks/{id}/test endpoint calls _validate_webhook_url() in mlflow/utils/validation.py only for the original URL while mlflow/webhooks/delivery.py follows redirects and re-resolves the hostname without pinning the validated address, allowing attackers to reach internal or cloud metadata services and receive response_status and response_body. This issue is fixed in version 3.15.0.

What to Do

Monitor MLflow's and lfprojects's web pages for any future patch releases.

References

Source	Reference
NVD	https://nvd.nist.gov/vuln/detail/CVE-2026-64849
CVE	https://www.cve.org/CVERecord?id=CVE-2026-64849

Source

Reference

NVD

https://nvd.nist.gov/vuln/detail/CVE-2026-64849

CVE

https://www.cve.org/CVERecord?id=CVE-2026-64849

KEV Required Action

Field	Value
KEV Link	https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Date Added to KEV	2026-08-19
Required Action Due Date	2026-09-02
Required Action	Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Field

Value

KEV Link

https://www.cisa.gov/known-exploited-vulnerabilities-catalog

Date Added to KEV

2026-08-19

Required Action Due Date

2026-09-02

Required Action

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.