CVE-2026-76833
@cgauge/yaml npm Package Arbitrary Code Execution via eval() YAML Tag
- State
- Published
- Severity
- 8.4 High
- Published
- Aug 20, 2026
- Updated
- Aug 20, 2026
- Reserved
- Aug 19, 2026
Description
@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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.4 High | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 7.8 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-95 Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
Affected Products
| Product | Versions |
|---|---|
@cgauge/yamlcgauge |
|
References
- GitHub Repositoryproduct
- GitHub GISTtechnical-description
- https://www.vulncheck.com/advisories/cgauge-yaml-npm-package-arbitrary-code-execution-via-eval-yaml-tagthird-party-advisory
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