Vowpal Wabbit — Rce (CVE-2026-44723)
Date: 2026-05
Affected: vowpalwabbit/vowpal_wabbit
Attack vector: rce
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-44723
CWE: CWE-1336
CWE-78
CVSS: 5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N)

Vowpal Wabbit is a machine learning system. The workflow .github/workflows/python_checks.yml embeds ${{ github.event.pull_request.title }} directly inside double-quoted bash strings in four separate steps across four jobs, each passing it as a CLI argument to the Python test script run_tests_model_gen_and_load.py. The shell interprets the expanded string before invoking Python, allowing an attacker to break out of the quotes and execute arbitrary commands on the runner. The pull_request trigger fires on PRs targeting any branch (branches: ['*']), with no additional access gate. This vulnerability is fixed by the 998e390e80a7e8192d7849b7784bc113dbd190ad commit.


Mitigations:

Architectural layers (MAESTRO):