Rust at Scale: An Added Layer of Security for WhatsApp
Jan 27, 2026Daniel Sommermann, Baojun Wang
Summary
WhatsApp has adopted Rust for its media consistency library, replacing 160,000 lines of C++ with 90,000 lines of Rust. This migration was driven by the need to mitigate memory safety vulnerabilities, as demonstrated by the Stagefright vulnerability. The Rust implementation offers performance and runtime memory usage advantages and has been rolled out to billions of users across multiple platforms. The 'Kaleidoscope' system was also developed to perform format checks and detect risk indicators in various file types.
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