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- 1Tiny regex bugs that brought down Cloudflare and Stack Overflow▼A regular expression took Cloudflare off the internet. Another took down Stack Overflow. Both written in an afternoon, l
Developers are revisiting how short, harmless-looking regular expressions knocked major services offline. The failures stemmed from catastrophic backtracking: a repeating group nested inside another repeating group, fed input that could not match, forcing the engine to try every possible split. Cloudflare and Stack Overflow both suffered such outages, and the pattern behind them can be written in an afternoon by anyone.