New “Brash” Flaw Exploits Blink Engine to Crash Browsers

A severe vulnerability, codenamed Brash by security researcher Jose Pino, has been disclosed, affecting the Blink rendering engine used in many Chromium-based browsers. According to the October 30, 2025, disclosure, the flaw can be exploited with a single malicious URL to make a browser crash within 15 to 60 seconds. The vulnerability presents a significant denial-of-service risk for users of popular web browsers built on the Chromium framework.

In a technical breakdown, Pino explained that the exploit “allows any Chromium browser to collapse… by exploiting an architectural flaw in how certain DOM operations are managed.” This discovery highlights a critical weakness that can be triggered remotely without complex user interaction, posing a direct threat to browser stability.

How the Brash Exploit Works

At its core, the Brash vulnerability stems from the lack of rate limiting on the “document.title” API. This oversight allows a malicious script to bombard the browser with an overwhelming number of Document Object Model (DOM) mutations per second. The browser’s rendering engine is unable to handle this massive influx of operations, causing it to consume excessive CPU resources. This not only leads to a rapid crash of the browser tab but also degrades overall system performance as the processor struggles to keep up with the resource-intensive process.

The attack is initiated through a multi-step process that begins with a preparation phase. During this first step, described as the “hash generation or preparation phase,” the attacker’s code preloads 100 unique hexadecimal strings, each 512 characters long, into the browser’s memory. These strings act as a seed for the subsequent flood of browser tab title changes, which ultimately triggers the system overload and subsequent crash.

Source: https://thehackernews.com/2025/10/new-brash-exploit-crashes-chromium.html