What’s Vulnerable › Vulnerabilities

CVE-2026-73088: Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats)

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-11 · updated 2026-09-09
• Weakness: CWE-248

Description

Browserslist is a configuration tool for sharing target browsers and Node.js versions between front-end tools. Prior to 4.28.7, normalizeStats() in node.js, reached unconditionally through getStat() and loadStat() on every browserslist() call, processes untrusted browserslist-stats.json, opts.stats, and CLI --stats data with an unguarded for...in loop and plain-object bracket access and assignment, allowing inherited Object.prototype keys including __proto__, toString, valueOf, constructor, hasOwnProperty, and isPrototypeOf to cause an uncaught TypeError or modify the prototype of the returned normalized object. This issue is fixed in version 4.28.7.

Affected products

• Npm Browserslist: before 4.28.7 — fixed in 4.28.7
• browserslist: before 4.28.7

How to fix

Upgrade to a fixed version: Npm Browserslist 4.28.7. Check the vendor advisory for mitigations.

References

• https://github.com/browserslist/browserslist/commit/f9914ad9effc865ccc27d816255625890b31ca51
• https://github.com/browserslist/browserslist/releases/tag/4.28.7
• https://github.com/browserslist/browserslist/security/advisories/GHSA-73wf-gq98-2v4g
• https://github.com/browserslist/browserslist/security/advisories/GHSA-73wf-gq98-2v4g

Get alerted when CVE-2026-73088 or the next vulnerability affects your stack