Known exploited vulnerability
CVE-2026-64849
The short answer
CVE-2026-64849 affects mlflow mlflow and is rated critical (CVSS 9.3). CISA added it to the Known Exploited Vulnerabilities catalog on 2026-08-19: attackers are using it, so patch it first. Fixed versions are published for mlflow (3.15.0).
What it is
MLflow is an open source AI engineering platform for agents, large language models, and machine learning models. Starting in 3.3.0 and 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.
Weakness: CWE-918.
Severity
9.3 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:N
Exploited (CISA KEV)
Yes, since Aug 19, 2026
Federal due date Sep 2, 2026
EPSS, next 30 days
10%
Higher than 96% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- Low
- Availability impact
- None
What CISA says to do
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…
Affected packages and fixed versions
| Package | Ecosystem | Fixed in | Advisory |
|---|---|---|---|
| mlflow | PyPI | 3.15.0 | GHSA-7gwp-5pfp-969j |
Is it in your code? Drop your lockfile into the free vulnerability check, or let vulnerability watch check your repository every day and open the upgrade as a pull request.
Affected products
mlflow. NVD's record lists the exact affected versions.
References
- github.com/mlflow/mlflow/commit/ba949522477cbd5915aa55d29b0cfad7d5ddf939 Patch
- github.com/mlflow/mlflow/issues/24179 ExploitIssue TrackingMitigation
- github.com/mlflow/mlflow/pull/24258 Issue TrackingPatch
- github.com/mlflow/mlflow/releases/tag/v3.15.0 Release Notes
- github.com/mlflow/mlflow/security/advisories/GHSA-7gwp-5pfp-969j ExploitVendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-64849 US Government Resource
Questions
Is CVE-2026-64849 being exploited?
Yes. CISA added CVE-2026-64849 to its Known Exploited Vulnerabilities catalog on 2026-08-19, with a federal remediation due date of 2026-09-02.
How do I fix CVE-2026-64849?
Upgrade to a fixed version: mlflow (PyPI) 3.15.0. CISA's 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…
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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