CVE-2026-73088: Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats)
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · CWE-1321, CWE-248
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
browserslist: browserslist
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/browserslist/browserslist/commit/f9914ad9effc865ccc27d816255625890b31… (opens in new tab)
- github.com/browserslist/browserslist/releases/tag/4.28.7 (opens in new tab)
- github.com/browserslist/browserslist/security/advisories/GHSA-73wf-gq98-2v4g (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)