Background <p>Social anxiety (SA) is characterized by cognitive control impairments, particularly in the processing of threat, yet how threat-laden environments modulate cognitive control over neutral stimuli remains unclear. This study examined whether threat context impairs the processing of neutral words in individuals with high social anxiety (HSA) through electrophysiological and oscillatory dynamics.</p> Methods <p>A total of 151 participants (HSA vs. low social anxiety, LSA) completed a Stroop task in two conditions: (1) threat context (neutral words intermixed with social threat words), and (2) neutral-onl<Emphasis Type="BoldItalic">y</Emphasis> (neutral words only). Behavioral responses (RTs), ERP (N2, N450, SP), and frontal-midline theta oscillations were analyzed.</p> Results <p>Threat context significantly prolonged RTs in HSA compared to LSA individuals. ERP data revealed that LSA individuals exhibited larger N450 and reduced SP under threat than under neutral-only conditions, indicating efficient conflict resolution. However, LSA individuals showed blunted N450 but amplified SP, suggesting prolonged attentional engagement with neutral stimuli in threat contexts. Time-frequency analyses further demonstrated that LSA participants increased frontal theta power in the threat context, whereas HSA individuals displayed suppressed theta activity, reflecting impaired top-down cognitive control. Threat contexts contaminate the processing of neutral stimuli in HSA individuals, marked by attenuated conflict detection (N450), increased attention engagement (SP), and deficient theta-mediated control.</p> Conclusion <p>These findings indicate that threat context impairs cognitive control of neutral word processing in HSA individuals when threat is possible, bridging cognitive and clinical models of attentional dysregulation.</p> Clinical trial number <p>Not applicable.</p>