Anthropic’s Opus 5 Nears Mythos 5 on Finding Bugs, but Falls Short on Exploits

Anthropic released Claude Opus 5, a cheaper alternative to its top model that performs nearly as well as Mythos 5 at finding software vulnerabilities but is significantly weaker at creating working exploits (automated attacks that demonstrate a vulnerability can be abused). The company deliberately limited Opus 5's training on offensive tasks and restricted it from generating exploits, allowing it to search source code for vulnerabilities while blocking binary scanning, penetration testing (simulated attacks to find weaknesses), and exploit generation.