Uncaught Exception in browserslist - CVE-2026-73088

Vulnerability details

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to 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. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.

Affected software

How to mitigate CVE-2026-73088

External 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

Related Security Bulletins

• Uncaught exception in Browserslist
• Multiple vulnerabilities in Platform Navigator in IBM Cloud Pak for Integration (CP4I)