CVE-2026-84452: CWE-942: Permissive Cross-domain Policy with Untrusted Domains in microsoft winml-cli
Description
Windows ML CLI is a command line tool for building portable, performant, and high-quality AI models for Windows ML. Prior to 0.4.0, the src/winml/modelkit/serve/cli_api.py component exposes WinML CLI commands through a localhost HTTP API without authentication and configures the allow_origins setting as a wildcard in both src/winml/modelkit/serve/cli_api.py and src/winml/modelkit/serve/app.py. A malicious website loaded by a user can send cross-origin requests to /v1/cli/build or /v1/cli/config and set the trust_remote_code parameter to true, which is converted to the --trust-remote-code command-line flag without validation. This reaches AutoConfig.from_pretrained with trust_remote_code=True in src/winml/modelkit/loader/_autoconfig.py and imports Python code from an attacker-controlled model repository, resulting in arbitrary code execution as the server user. This issue is fixed in version 0.4.0.
CVSS v4.0
Score 8.6high
Affected software
microsoft
winml-cli
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Microsoft winml-cli versions prior to 0.4.0 have a security flaw in the src/winml/modelkit/serve/cli_api.py and src/winml/modelkit/serve/app.py components where the allow_origins setting is configured as a wildcard, allowing cross-origin requests without authentication. This permits a malicious website to invoke WinML CLI commands via the localhost HTTP API endpoints /v1/cli/build or /v1/cli/config and set the trust_remote_code parameter to true. This parameter is passed unchecked to AutoConfig.from_pretrained, which imports Python code from an attacker-controlled model repository, resulting in arbitrary code execution with the privileges of the server user. The vulnerability is addressed in version 0.4.0.
Potential Impact
An attacker can exploit this vulnerability by tricking a user into visiting a malicious website that sends cross-origin requests to the vulnerable localhost API. This leads to arbitrary code execution on the victim's machine with the permissions of the server user running winml-cli. The impact includes potential full compromise of the affected system.
Mitigation Recommendations
This vulnerability is fixed in winml-cli version 0.4.0. Users should upgrade to version 0.4.0 or later to remediate this issue. No other official remediation or temporary fixes are documented. Until upgrading, users should avoid loading untrusted websites while the vulnerable service is running.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-01T20:05:09.423Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a987b11acd9273b49a503d8
Added to database: 09/02/2026, 19:37:53 UTC
Last enriched: 09/07/2026, 13:02:54 UTC
Last updated: 10/17/2026, 18:48:23 UTC
Views: 84
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