Top reverse engineer beats Flare-ON CTF in 2 hours with Claude, as Opus cracks a challenge that took experts 6 days

IxyCRO · reddit · 2026-09-28

A Europe-leading reverse engineer, who historically needed 10-12 days to finish the grueling 11-task Flare-ON CTF, completed this year's challenge in just 2 hours using AI on a Claude Pro plan — without even hitting the 5-hour usage cap. For the final task, which took human experts 5-6 days in past years, he simply uploaded the Linux binaries and told Opus 5.5 to "do your thing and find the flag"; it autonomously worked for 20 minutes and produced the correct flag. Dozens of players finished all 11 levels overnight after the challenge opened. The poster, a cybersecurity professional, says the result shattered his expectation that AI progress would slow down.

Related event: Top Reverse Engineer Clears Hardest CTF in 2 Hours with Claude(2 posts)→

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