CVE-2026-84452

Windows ML CLI: CORS misconfig enables localhost RCE

HIGH
8.6
CVSS Score
Published: September 2, 2026 at 07:22 PM UTC
Updated: September 28, 2026 at 11:10 PM UTC
1 product affected across 1 vendorWindows ML CLI

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Severity
HIGH8.6
Exploit prediction
EPSS 2%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.4.0
Affected range stops below 0.4.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.6HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-942CWE-306

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