CVE-2026-4035

Environment Variable Resolution Vulnerability in mlflow/mlflow

State
Published
Severity
9.1 Critical
Published
Jun 3, 2026
Updated
Aug 14, 2026
Reserved
Mar 12, 2026

Read the record on cve.org

Description

A vulnerability in mlflow/mlflow versions prior to 3.11.0 allows for the resolution of environment variables in AI Gateway secrets, which can be exploited to exfiltrate sensitive server-side environment credentials to an attacker-controlled endpoint. This issue arises because the `api_key` field in gateway secrets can accept `$ENV_VAR` references, which are resolved against the MLflow server's environment during runtime. The resolved secrets are then sent in provider authentication headers to the configured upstream `api_base`. This vulnerability can be exploited by low-privileged authenticated users in basic-auth deployments or by unauthenticated users in default deployments without `basic-auth`. The impact includes potential leakage of sensitive credentials such as cloud artifact credentials (`AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`), which could lead to artifact poisoning and cross-boundary code execution in downstream environments. The issue is fixed in version 3.11.0.

Scores

CVSSScoreVectorSource
3.09.1 CriticalCVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L@huntr_ai
3.17.7 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:Nredhat-SADP

Weaknesses

  • CWE-201 Insertion of Sensitive Information Into Sent Data

Affected Products

ProductVersions
mlflow/mlflowmlflow
  • before 3.11.0Affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.