ZDI-26-846: MLflow Webhook Server-Side Request Forgery Vulnerability
Affects MLflowSource Zero Day Initiative
Exploited in the wild · KEV due 2 Sep 2026 · public detection template (Nuclei) · 10% EPSS : apply the vendor's fix or mitigations to MLflow now.
Data as of 30 Oct 2026, 11:52 UTC
- KEV deadline
- US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
- EPSS
- 10.0% chance of exploitation in 30 days – higher than 95% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:L/A:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 17 Aug 2026
Detectable: evidence found.
nuclei template: MLflow Webhook SSRF - Unauthenticated Full-Read via Redirect Bypass
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: evidence found.
Listed in CISA KEV 2 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by GitHub, Inc.
, 28 days before disclosure
CVE published
on cve.org
, t = 0
Added to CISA KEV (opens in a new tab)
exploitation confirmed
, 2 days after disclosure
KEV remediation due
US federal deadline
, 16 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What 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 evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
- github.com/mlflow/mlflow/pull/24258 (opens in a new tab)
- github.com/mlflow/mlflow/issues/24179 (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (opens in a new tab)
- cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-64849 (opens in a new tab)
Description
A server-side request forgery (SSRF) vulnerability in MLflow's webhook feature allows authenticated remote attackers to initiate arbitrary server-side requests. The vulnerability has a medium severity rating with a CVSS score of 6.8 assigned by ZDI. No specific affected versions or patches are provided.