Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats) — GHSA-73WF-GQ98-2V4G

Summary

## Vulnerability Details **File**: `node.js` **Function**: `normalizeStats()` (line ~214), reached from `getStat()` (called **unconditionally** on every `browserslist()` call) and `loadStat()` ### Root Cause ```js function normalizeStats(data, stats) { if (!data) { data = {} } if (stats && 'dataByBrowser' in stats) { stats = stats.dataByBrowser } if (typeof stats !== 'object') return undefined var normalized = {}…

Timeline

Published by source

2026-09-01

Risk context

• Reported severity or threat level: high.
• Reported CVSS score: 7.5 out of 10.
• Reported EPSS value: 0.00361.
• Review exposure for the affected product or family: npm: browserslist.

Product

npm: browserslist

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-73WF-GQ98-2V4G

Source

GitHub

Vendor

GitHub

Published by source

2026-09-01

Last source activity

2026-09-01

Additional identifiers

CVE-2026-73088

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.