Chrome Modernizes XML Parsing: Replacing libxml2 with Rust for Enhanced Security and Performance

Introduction: The Need for Change Chrome’s decision to replace libxml2 , a C-based XML parser, with a Rust-based solution is rooted in a convergence of technical limitations, security risks, and evolving industry standards. At the core of this shift lies the inherent vulnerability of C’s manual memory management , which has historically been a breeding ground for critical security flaws. In the context of XML parsing, where data from untrusted sources is routinely processed, C’s lack of built-in memory safety guarantees—such as preventing buffer overflows or use-after-free errors —poses a systemic risk. These vulnerabilities are not theoretical; they are mechanistically tied to C’s reliance on developer discipline for memory allocation and deallocation , a process prone to human error and exploitation. The specific limitations of libxml2 further exacerbated these risks. Despite its widespread use, libxml2’s codebase has accumulated technical debt over decades , making it increasingly d