# CVE-2026-118623: MLflow PickleEvaluationArtifact deserialization of untrusted data

Source: https://junglewise.ai/threats/cve-2026-118623-mlflow-pickleevaluationartifact-deserialization-of-untrusted  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-04. Updated: 2026-11-04  
License: CC BY 4.0 with a link back

CVE-2026-118623 · Severity: high · CVSS 7.8 · Published 2026-11-04

MLflow is an open-source platform for managing machine learning workflows and artifacts. This vulnerability allows attackers to execute arbitrary code by crafting malicious pickle files that MLflow will deserialize without proper validation. An attacker can gain full control of the system running MLflow if they can trick a user into opening or visiting a malicious file or page.

Technologies: [Mlflow](https://junglewise.ai/threats/technologies/mlflow-mlflow). Vendors: [MLflow](https://junglewise.ai/threats/vendors/mlflow).

## Quick answers

**Is CVE-2026-118623 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-118623 being exploited in the wild.

**How severe is CVE-2026-118623?** High severity, with a CVSS score of 7.8, published 4 November 2026.

**Which products and versions are affected?** MLflow MLflow.

**Is there a fix for CVE-2026-118623?** Yes: fixed in MLflow 3.13.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-118623 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-118623?** Check whether you run Mlflow. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in MLflow 3.13.0

## Technical details

The vulnerability exists in MLflow's PickleEvaluationArtifact parser, which deserializes pickle files without validating the data source. An attacker can craft a malicious pickle file that executes arbitrary Python code during deserialization. User interaction is required (opening a malicious file or visiting a malicious page), but exploitation results in arbitrary code execution in the process context.

## Affected products

- MLflow MLflow

## Timeline

- 2026-03-25: disclosed: Vulnerability reported to vendor
- 2026-10-29: advisory: Coordinated public release of advisory

## References

- [https://www.zerodayinitiative.com/advisories/ZDI-26-839/](https://www.zerodayinitiative.com/advisories/ZDI-26-839/)

## Related threats

- [MLflow path traversal in FileStore log outputs API](https://junglewise.ai/threats/cve-2026-127202-mlflow-before-3-18-0-using-the-filestore-backend-contains-a-path)
- [MLflow get-artifacts server-side request forgery information disclosure](https://junglewise.ai/threats/cve-2026-118628-mlflow-get-artifacts-server-side-request-forgery-information)
- [MLflow SHAP load_explainer deserialization of untrusted data](https://junglewise.ai/threats/cve-2026-118627-mlflow-shap-load-explainer-deserialization-of-untrusted-data)
- [MLflow Tracking Server missing authorization in get_endpoints](https://junglewise.ai/threats/cve-2026-118625-mlflow-tracking-server-missing-authorization-privilege)
- [MLflow Tracking Server authorization bypass in Jobs API](https://junglewise.ai/threats/cve-2026-118624-mlflow-tracking-server-jobs-missing-authorization-information)