Commit-Message-Augmented Static Analysis of Cross-Site Scripting Fixes in Java Web Applications
Cross-Site Scripting (XSS) remains a common and high-impact web vulnerability. Detecting XSS with high precision is difficult because exploitability depends on end-to-end data flow (sources, sanitizers, and sinks), framework-specific rendering semantics, and the correctness of context-aware output encoding. Although secure development lifecycles increasingly integrate static application security testing (SAST) into CI/CD pipelines, practical adoption is often limited by false positives and incomplete modeling of project-specific sanitization and templating behavior. In parallel, machine learning (ML) approaches show promise for learning vulnerability-relevant patterns from code, but they depend on the availability of realistic labeled data. This paper studies a low-cost repository-native signal that is routinely available but underused in ML-assisted static analysis: commit messages. We propose a mining and weak-labeling pipeline for Java repositories that identifies candidate XSS-fix commits using message heuristics grounded in OWASP guidance and CWE taxonomy, aligns commit messages with pre-/post-change code contexts extracted from diffs, and trains classifiers under two feature settings: (i) code-only and (ii) code+commit-message fusion. Across three model families (Random Forest, TextCNN, and BiLSTM), commit-message fusion consistently improves F1 and AUPRC and reduces false positives, suggesting that developer intent provides a useful auxiliary signal for security triage.