Words Speak Louder Than Code: Investigating Cognitive Heuristics in LLM-Based Code Vulnerability Detection

Researchers and practitioners increasingly apply Large Language Models (LLMs) for automated vulnerability detection. Recent work has shown that LLMs are susceptible to the same cognitive heuristics that bias human judgment. Yet, no work has investigated whether these heuristics affect a model's assessment of code vulnerabilities. In this paper, we present the first systematic exploration of cognitive heuristics in LLM-driven code vulnerability detection. We introduce a controlled framework that holds the code fixed and only varies the surrounding context to trigger three cognitive heuristics: the halo effect through author attribution, the framing effect through task objectives and consequences, and the anchoring effect through prior analysis results. Within this framework, we evaluate eight LLMs across three programming languages and perform both quantitative and code-level analyses. Our findings demonstrate that all evaluated models are susceptible to these heuristics. Cross-model average susceptibility is highest for framing at 33.2%, followed by anchoring at 23.5% and halo at 18.4%. Code-level analysis reveals that vulnerabilities that require semantic reasoning for detection are more susceptible to cognitive heuristics than those identifiable through pattern matching. Furthermore, models often change their verdict from safe to vulnerable based on the cognitive condition, without accurately identifying the actual vulnerability. To highlight the practical impact, we demonstrate a proof-of-concept black-box cognitive attack that can suppress up to 97% of previously detected vulnerabilities. These findings indicate that cognitive susceptibility is a consistent and exploitable property of LLM-based vulnerability detection.

Inceptive Transformers: Enhancing Contextual Representations through Multi-Scale Feature Learning Across Domains and Languages

Conventional transformer models typically compress the information from all tokens in a sequence into a single \texttt{[CLS]} token to represent global context-- an approach that can lead to information loss in tasks requiring localized or hierarchical cues. In this work, we introduce \textit{Inceptive Transformer}, a modular and lightweight architecture that enriches transformer-based token representations by integrating a multi-scale feature extraction module inspired by inception networks. Our model is designed to balance local and global dependencies by dynamically weighting tokens based on their relevance to a particular task. Evaluation across a diverse range of tasks including emotion recognition (both English and Bangla), irony detection, disease identification, and anti-COVID vaccine tweets classification shows that our models consistently outperform the baselines by 1\% to 14\% while maintaining efficiency. These findings highlight the versatility and cross-lingual applicability of our method for enriching transformer-based representations across diverse domains.