npm package report

Is yayson safe?

1 known vulnerability, worst severity CRITICAL.

cvss

9.1

how bad it is if exploited, out of 10

epss

0.80%

chance of exploitation in the next 30 days

xyz score

4.0

CyberXYZ composite, out of 10

fig. 01 — GHSA-325j-mg25-8q58, the advisory selected below

// advisories

GHSA-325j-mg25-8q58

CRITICALCVE-2026-61534

Store/LegacyStore key internal lookup tables by the type, id, and relationship names from a JSON:API document. Because these were plain objects, a document with type: "proto" writes onto Object.prototype, polluting every object in the process.

Affected: <= 4.2.0, >=0, <4.3.0
Fixed in: 4.3.0
Weakness: CWE-1321
Published: 2026-09-11
Source: github

GHSA NVD MITRE reference

// dependencies

0 direct

// ai model usage

Tracked for PyPI packages. HuggingFace models declare Python dependencies, so npm packages are not covered.

Checked 2026-09-22 at 01:43 UTC. The most recent advisory here was published 2026-09-11. Updated continuously from NVD, GHSA, OSV and CNA feeds.

Is yayson safe? npm package security report | CyberXYZ