Critical Firefox Bug Leaves 180M Users Exposed

A subtle but dangerous memory flaw quietly shipped in Firefox for six months — affecting more than 180 million users — before security researchers uncovered it.

The vulnerability allowed attackers to corrupt memory and potentially execute arbitrary code through malformed WebAssembly payloads.

“Aisle’s autonomous AI system uncovered this subtle boundary-condition vulnerability during our WebAssembly security deep dive, revealing meaningful memory-safety risks for roughly 180 million Firefox users,” Stanislav Fort, founder and chief scientist at AISLE, said in a blog post.

He added, “Mozilla moved quickly to deploy a fix. Modern browsers are some of the most secure and rigorously engineered platforms in existence, and this finding highlights the importance of continuous, AI-driven security research to keep them safe for users worldwide.”

The hidden code error that exposed Firefox users

At the core of the vulnerability (CVE-2025-13016) is a subtle pointer arithmetic mistake in Firefox ...