Jul 2026· Machine Learning and Knowledge Extraction· Vol abs/2607.21069, pp. 258· 0 citations· 42 references
Computer Science
TL;DR
Testing three delivery mechanisms–supervised fine-tuning, a dual-head classification loss, and reinforcement learning with a dense reward derived from the normalised penalty finds that supervised approaches consistently regress below the zero-shot baseline under distribution shift, while GRPO succeeds and generalises across independent training seeds.
Abstract
The original ALPHA benchmark introduced a taxonomy-aware penalty for evaluating CWE-level vulnerability prediction in Python and proposed that the penalty could theoretically also serve as a training signal. This paper tests that proposal empirically, comparing three delivery mechanisms–supervised fine-tuning, a dual-head classification loss, and reinforcement learning with a dense reward derived from the normalised penalty. We find that supervised approaches consistently regress below the zero-shot baseline under distribution shift, while GRPO succeeds and generalises across independent training seeds. Using a default, non-test-informed configuration, GRPO reduces the mean cumulative ALPHA penalty of Qwen2.5-Coder-7B-Instruct on Security Hardening and Adversarial Testing (SVEN) by 13.5%. A further test-selected configuration reduces the mean penalty by 22.9% (27.9% in the best-observed run), reaching statistical parity with its 4.5× larger zero-shot teacher. Our experiments show that reinforcement learning outperforms the alternative delivery mechanisms we test. We conclude that delivery mechanism, rather than the specific hierarchical structure of the reward, is the primary variable—though whether taxonomy-aware structure contributes further remains an open question.
Machine learning-based credit scoring is increasingly central to Peer-to-Peer (P2P) lending, yet its resilience to adversarial manipulation, where applicants strategically alter self-reported inputs to secure favourable decisions, remains poorly understood. Most adversarial-robustness evidence comes from image and text domains and evaluates a single attack against a matching defence, offering little guidance on how defences generalise across attack types in tabular credit data. We address this with a systematic train-test robustness benchmark on a large Lending Club subset, spanning three model families (logistic regression, a feed-forward neural network, and a transformer for tabular data) and four attacks confined to applicant-mutable features: Fast Gradient Sign Method (FGSM), Projected Gradient Descent (PGD), Salt-and-Pepper (S&P) noise, and DeepFool, plus a mixed-attack regime. Across a full grid evaluated with stratified cross-validation, adversarial training sharply improves robustness against the attack it is trained on and transfers well within the gradient-based family, but transfers weakly to non-gradient corruption, so single-attack defences overstate real-world resilience. Mixed training delivers the most balanced robustness across heterogeneous attacks while preserving clean-test performance, supporting multi-attack stress testing in credit-model governance.
Gijs A. F. Niewzwaag, Marijn G. S. Veth, Manuele Massei et al.· 0 citations
D3Adapter is presented, a threat-aware framework that unifies adversarial example detection (AED) and robust inference and scalability across datasets with varying numbers of classes is studied, showing that unified detection and robust inference can be achieved with predictable overhead proportional to the number of adapters.
A failure-aware adversarial retrieval-augmented framework for improving robustness in natural language understanding that combines retrieval, automated validation, contextual-bandit failure selection, and controlled adversarial retraining, enables scalable robustness improvement without additional human annotation.
Single domain generalization (SDG) aims to learn a model from one labeled source domain that generalizes to unseen target domains. A common strategy is to enrich the source distribution with augmented or generated samples, and recent text-to-image (T2I) diffusion models provide a strong generative prior for this purpose. However, diversity alone is insufficient for robust generalization, because useful generated samples should also capture variations that the current classifier finds difficult. Motivated by distributionally robust optimization (DRO), we define a semantic ambiguity set in the class-conditional generative space of a pretrained T2I model and search it for samples with high classification loss under the current classifier. To this end, we introduce PAPT++, a risk-aware adversarial generation-training framework for SDG. PAPT++ first learns diverse semantic reference images for each class through image-text alignment and intra-class diversity regularization. These references then serve as denoising targets during classifier-guided diffusion synthesis, reducing semantic drift while guiding generation toward challenging variations. The generated samples are combined with the source data to update the classifier, and the updated classifier guides the next synthesis round in return. In this way, PAPT++ progressively exposes the classifier to challenging yet semantically consistent variations. Extensive experiments on standard SDG benchmarks demonstrate the superiority of the proposed PAPT++ method and the effectiveness of its main components.
Zhipeng Xu, De Cheng, Xinyang Jiang et al.· 0 citations
Results show that security assessment of self-supervised distillation should include executable training logic in addition to model weights and visible data.
Da Xiao, Tongke Fan, Ning Dong et al.· Electronics· 0 citations
A novel general neural network repair paradigm termed NCCDA (Neuron-wise Class-Conditional Distribution Alignment), which theoretically prove a generalization error bound under small-sample settings based on Rademacher complexity, providing formal guarantees.
Liming Bao, Yan Wang, Tao Sun· Proceedings of the 32nd ACM...· 0 citations
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