Vulnerability · Published Aug 11, 2026 · Assigned by GitHub_M
CVE-2026-73088Browserslist: Uncaught crash / prototype write via untrusted browserslist-stats.json custom stats (normalizeStats)
High 7.5
In plain English
A high-severity prototype pollution in browserslist from browserslist. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-browserslist | no fix listed | DEBIAN-CVE-2026-73088 |
| Debian:13 | node-browserslist | no fix listed | DEBIAN-CVE-2026-73088 |
| Debian:14 | node-browserslist | 4.28.7+~cs8.16.65-1 | DEBIAN-CVE-2026-73088 |
| Ubuntu:22.04:LTS | node-browserslist | no fix listed | UBUNTU-CVE-2026-73088 |
| Ubuntu:24.04:LTS | node-browserslist | no fix listed | UBUNTU-CVE-2026-73088 |
| Ubuntu:26.04:LTS | node-browserslist | no fix listed | UBUNTU-CVE-2026-73088 |
| npm | browserslist | 4.28.7 | GHSA-73wf-gq98-2v4g |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| browserslist | browserslist | < 4.28.7 |
Weakness: CWE-1321, CWE-248 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H