Vulnerability details
CVE-2026-76833
cgauge @cgauge/yaml
@cgauge/yaml npm Package Arbitrary Code Execution via eval() YAML Tag
CVSS 4.0
8.4High
Official 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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.4High | 4.0 | CVEProject cvelistV5 (CNA) (VulnCheck) | 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 |
| 7.8High | 3.1 | CVEProject cvelistV5 (CNA) (VulnCheck) | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| cgauge | @cgauge/yaml | v ≤ 0.27.0 | CVEProject cvelistV5 (CNA) |
References and advisories
3- https://github.com/cgauge/packages product
- https://www.vulncheck.com/advisories/cgauge-yaml-npm-package-arbitrary-code-execution-via-eval-yaml-tag third-party-advisory
- https://gist.github.com/arjunjaincs/35da3a80b4b16f324f194acec18489ba technical-description
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Details
- Published
- 2026-08-20
- Last updated
- 2026-08-20
- State
- Published
- Assigner (CNA)
- VulnCheck
Exploit prediction (EPSS)
0.21%
Probability of exploitation in 30 days
12.5%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- Proof of concept
- Technical impact
- Total
Weaknesses (CWE)
- CWE-95Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')