CVE-2026-76833: Cgauge @cgauge/yaml

High severity, CVSS 7.8. EPSS: 0.2% chance of exploitation in the next 30 days.

@cgauge/yaml npm package contains an arbitrary code execution vulnerability that allows attackers to execute arbitrary JavaScript by embedding a custom !js YAML tag whose construct callback unconditionally calls eval() on attacker-supplied string values during document parsing. Any application parsing untrusted YAML input with this library exposes full Node.js runtime authority, including environment variable access, filesystem read/write, network access, and subprocess execution, with no safe-mode alternative or opt-out mechanism available.

Affected products

• Cgauge @cgauge/yaml: up to and including 0.27.0

Published 2026-08-20. Last modified 2026-09-24.