CVE-2026-4035
Environment Variable Resolution Vulnerability in mlflow/mlflow
- Published
- Updated
- Reserved
- Assigned by
- @huntr_ai
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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| @huntr_aiCNA (assigner) | 3.0 | Critical9.1 | CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L |
| redhat-SADPADP (enrichment) | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
| NVDNVD · Modified | 3.1 | High7.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.52% · top 56% of all CVEs (5 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Weakness
Affected products
- affected unspecified – < 3.11.0
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPImlflowGHSA-g35p-px32-whv6 (opens in a new tab)
References (5)
- https://huntr.com/bounties/f8e591a0-0f19-4910-b82e-16c9956f2233 (opens in a new tab)exploit
- https://github.com/mlflow/mlflow/commit/4a3f2f720cb4f058c9e0c5b883e0acc9ab64a7f3 (opens in a new tab)
- https://access.redhat.com/security/cve/CVE-2026-4035 (opens in a new tab)vdb-entryx_refsource_REDHAT
- RHBZ#2484318 (opens in a new tab)issue-trackingx_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4035.json (opens in a new tab)x_sadp-csaf-vex
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-g35p-px32-whv6 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-4035)Record last updated .