Vibe Coding Cut Task Time 27% and Raised Security Vulnerabilities in the Same Trial

arXiv 2609.09560·medium signalXBlueskyLinkedInCopy link

arXiv 2609.09560 (2026-09-09) ran 30 professional developers and advanced computing students through equivalent tasks under three conditions (traditional, AI-assisted, and AI-led conversational programming) with repeated-measures ANOVA plus thematic analysis. Vibe coding cut completion time 27% versus traditional and 12% versus AI-assisted, scored SUS 71.4 and NASA-TLX 55.5, but produced lower maintainability indices and more security vulnerabilities. The thematic analysis ties the security regression specifically to perceived loss of control, meaning reduced transparency and less validation of what the model emitted.