# An Empirical Evaluation of LLM-Based Approaches for Code Vulnerability Detection: RAG, SFT, and Dual-Agent Systems

arXiv: https://arxiv.org/abs/2601.00254 · HTML: https://mlsanity.com/paper/2601.00254/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Placed in Privacy and security of RAG, one of 15 directions in Retrieval-augmented generation.
- Builds on 5 of its 13 references that are in the map.
- First posted on arXiv 1 Jan 2026.

## Placed in

- Retrieval-augmented generation / [Privacy and security of RAG](https://mlsanity.com/rag/privacy-and-security-of-rag/)
- LLM agents and tool use / [Agent threats, guardrails and governance](https://mlsanity.com/agents/agent-threats-guardrails-and-governance/)

## Builds on (most cited first, 5 of 5)

- [LoRA: Low-Rank Adaptation of Large Language Models](https://mlsanity.com/paper/2106.09685/) (2021)
- [Vul-RAG: Enhancing LLM-based Vulnerability Detection via Knowledge-level RAG](https://mlsanity.com/paper/2406.11147/) (2024)
- [Finetuning Large Language Models for Vulnerability Detection](https://mlsanity.com/paper/2401.17010/) (2024)
- [Security Vulnerability Detection with Multitask Self-Instructed Fine-Tuning of Large Language Models](https://mlsanity.com/paper/2406.05892/) (2024)
- [VulScribeR: Exploring RAG-based Vulnerability Augmentation with LLMs](https://mlsanity.com/paper/2408.04125/) (2024)

## Abstract (arXiv)

The rapid advancement of Large Language Models (LLMs) presents new opportunities for automated software vulnerability detection, a crucial task in securing modern codebases. This paper presents a comparative study on the effectiveness of LLM-based techniques for detecting software vulnerabilities. The study evaluates three approaches, Retrieval-Augmented Generation (RAG), Supervised Fine-Tuning (SFT), and a Dual-Agent LLM framework, against a baseline LLM model. A curated dataset was compiled from Big-Vul and real-world code repositories from GitHub, focusing on five critical Common Weakness Enumeration (CWE) categories: CWE-119, CWE-399, CWE-264, CWE-20, and CWE-200. Our RAG approach, which integrated external domain knowledge from the internet and the MITRE CWE database, achieved the highest overall accuracy (0.86) and F1 score (0.85), highlighting the value of contextual augmentation. Our SFT approach, implemented using parameter-efficient QLoRA adapters, also demonstrated strong performance. Our Dual-Agent system, an architecture in which a secondary agent audits and refines the output of the first, showed promise in improving reasoning transparency and error mitigation, with reduced resource overhead. These results emphasize that incorporating a domain expertise mechanism significantly strengthens the practical applicability of LLMs in real-world vulnerability detection tasks.