Bitsec (Subnet 60) found 160+ vulnerabilities in a client codebase versus Fable 5’s 60 — including five criticals the frontier model missed entirely. Fable 5 had to be jailbroken to run the test at all. Bitsec’s output was broader; Fable 5’s was cleaner. The test was conducted days before the US government forced Anthropic to take Fable 5 offline globally.