Sakana AI has released Fugu-Cyber (model ID is fugu-cyber-v1.0), a cybersecurity-specialized addition to its Fugu orchestration family. It is not just a new frontier model. It is a third endpoint on the Fugu orchestrator, tuned for security reasoning. Sakana launched that orchestrator a month earlier.
Sakana reports a success rate of 86.9% on CyberGym and 72.1% on CTI-REALM. It describes those results as comparable to cyber-focused frontier models such as GPT-5.5-Cyber and Claude Mythos Preview.
What the two benchmarks actually measure
The two evaluations sit at opposite ends of a security workflow:
CyberGym is a UC Berkeley benchmark of 1,507 real-world vulnerabilities across 188 OSS-Fuzz projects. In its main task, an agent receives a vulnerability description and an unpatched codebase. It must write a proof-of-concept that crashes the pre-patch build but not the post-patch build. That verification step is what makes the benchmark hard to game.
