---
id: CVE-2026-76833
title: >-
  @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-suppli…
summary: >-
  @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-suppli…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-95
published: '2026-08-20'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:06:30.133'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76833'
references:
  - url: 'https://gist.github.com/arjunjaincs/35da3a80b4b16f324f194acec18489ba'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/cgauge/packages'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/cgauge-yaml-npm-package-arbitrary-code-execution-via-eval-yaml-tag
    label: disclosure@vulncheck.com
  - url: 'https://gist.github.com/arjunjaincs/35da3a80b4b16f324f194acec18489ba'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00221
epssPercentile: 0.11272
ingestedAt: '2026-09-24T20:51:40.211Z'
---

## Overview

@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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.