One "Fix This Code" Prompt Away from a Production Incident

Short summary

AI coding tools can introduce unintended security changes when given vague prompts like "fix this code." The Fable 5 incident showed how diff blindness, auto-accept workflows, and prompt scope creep allowed regressions to bypass review and reach production. Deterministic quality gates checking complexity, dependencies, test coverage, and fail-open/fail-closed patterns can catch these issues automatically.

• •Vague AI prompts like "fix this code" produce changes broader than the immediate problem, with unintended side effects on system constraints
• •Three endemic patterns (diff blindness, auto-accept workflows, prompt scope creep) allow AI-generated security regressions to ship to production
• •Deterministic quality gates checking cyclomatic complexity, new dependencies, test coverage, and security patterns can catch these issues in under a second

Generated with AI, which can make mistakes.