Vulnerability Intelligence Report
@cgauge/yaml npm Package Arbitrary Code Execution via eval() YAML Tag
CVE-2026-76833
@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.
No Active Exploit Signals
CVSS Base Score
8.4
HIGH
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
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SSVC Action
—
Weaknesses (CWE)
CWE-95 ↗Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| cgauge | @cgauge/yaml | 0 <= 0.27.0 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | VulnCheck · Bug Bounty Provider · USA |
| Reserved | 2026-08-19T20:34:00 |
| Published | 2026-08-20T13:33:14 |
| Patch Date | 2026-08-19 |
| Last Updated | 2026-08-20T14:29:17 |
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