SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-64849

MLflow Server-Side Request Forgery Vulnerability

KEVCRITICAL 9.3EPSS 16.4%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 2 September 2026). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

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.

CVSS 3.1
9.3 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
EPSS
16.41% probability · 97th percentile
CISA KEV
Listed 19 August 2026 · due 2 September 2026
Weakness
CWE-918
Affected
lfprojects/mlflow
Source
security-advisories@github.com

CISA notes

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. https://github.com/mlflow/mlflow/pull/24258 ; https://github.com/mlflow/mlflow/issues/24179 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2026-64849

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.