Browserslist Browserslist vulnerabilities

Browserslist is a configuration tool for sharing target browsers and Node.js versions between front-end tools. Prior to 4.28.7, index.js retains every distinct `(queries, context)` result in cache and every parseQueries() AST in parseCache without a size cap, TTL, or eviction, allowing an attacker who can influence repeated browserslist() query values, including valid since `<year>-<month>-<day>` queries, to bypass the caller-controlled BROWSERSLIST_DISABLE_CACHE mitigation and cause linear memory growth followed by an out-of-memory process crash. This issue is fixed in version 4.28.7.

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.