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Zhexin Zhang

16 accepted papers

2026

BARREL: Boundary-Aware Reasoning for Factual and Reliable LRMs

ICLR 2026poster

Recent advances in Large Reasoning Models (LRMs) have shown impressive capabilities in mathematical and logical reasoning. However, current LRMs rarely admit ignorance or respond with “I don’t know”. Instead, they often produce incorrect answers while showing undue confidence, raising concerns about…

Cited by 7SourcecodeScholar
2026

Be Careful When Fine-tuning On Open-Source LLMs: Your Fine-tuning Data Could Be Secretly Stolen!

ICLR 2026poster

Fine-tuning on open-source Large Language Models (LLMs) with proprietary data is now a standard practice for downstream developers to obtain task-specific models. Surprisingly, we reveal a new and concerning risk along with the practice: the provider of the open-source LLMs can later extract the pri…

Cited by 0SourcecodeScholar
2026

When Smiley Turns Hostile: Interpreting How Emojis Trigger LLMs’ Toxicity

AAAI 2026technical

Emojis are globally used non-verbal cues in digital communication, and extensive research has examined how large language models (LLMs) understand and utilize emojis across contexts. While usually associated with friendliness or playfulness, it is observed that emojis may trigger toxic content gener

Cited by 0SourcePDFScholar
2025

Guiding not Forcing: Enhancing the Transferability of Jailbreaking Attacks on LLMs via Removing Superfluous Constraints

ACL 2025long

Jailbreaking attacks can effectively induce unsafe behaviors in Large Language Models (LLMs); however, the transferability of these attacks across different models remains limited. This study aims to understand and enhance the transferability of gradient-based jailbreaking methods, which are among t…

2025

LongSafety: Evaluating Long-Context Safety of Large Language Models

ACL 2025long

As Large Language Models (LLMs) continue to advance in understanding and generating long sequences, new safety concerns have been introduced through the long context. However, the safety of LLMs in long-context tasks remains under-explored, leaving a significant gap in both evaluation and improvemen…

2024

Defending Large Language Models Against Jailbreaking Attacks Through Goal Prioritization

ACL 2024long

While significant attention has been dedicated to exploiting weaknesses in LLMs through jailbreaking attacks, there remains a paucity of effort in defending against these attacks. We point out a pivotal factor contributing to the success of jailbreaks: the intrinsic conflict between the goals of bei…

2024

SafetyBench: Evaluating the Safety of Large Language Models

ACL 2024long

With the rapid development of Large Language Models (LLMs), increasing attention has been paid to their safety concerns. Consequently, evaluating the safety of LLMs has become an essential task for facilitating the broad applications of LLMs. Nevertheless, the absence of comprehensive safety evaluat…

2024

ShieldLM: Empowering LLMs as Aligned, Customizable and Explainable Safety Detectors

EMNLP 2024finding

The safety of Large Language Models (LLMs) has gained increasing attention in recent years, but there still lacks a comprehensive approach for detecting safety issues within LLMs’ responses in an aligned, customizable and explainable manner. In this paper, we propose ShieldLM, an LLM-based safety de…

2023

ETHICIST: Targeted Training Data Extraction Through Loss Smoothed Soft Prompting and Calibrated Confidence Estimation

ACL 2023long

Large pre-trained language models achieve impressive results across many tasks. However, recent works point out that pre-trained language models may memorize a considerable fraction of their training data, leading to the privacy risk of information leakage. In this paper, we propose a method named E…

2023

InstructSafety: A Unified Framework for Building Multidimensional and Explainable Safety Detector through Instruction Tuning

EMNLP 2023long findings

Safety detection has been an increasingly important topic in recent years and it has become even more necessary to develop reliable safety detection systems with the rapid development of large language models. However, currently available safety detection systems have limitations in terms of their v…

Cited by 0SourceScholar
2023

MoralDial: A Framework to Train and Evaluate Moral Dialogue Systems via Moral Discussions

ACL 2023long

Morality in dialogue systems has raised great attention in research recently. A moral dialogue system aligned with users’ values could enhance conversation engagement and user connections. In this paper, we propose a framework, MoralDial to train and evaluate moral dialogue systems. In our framework…

2023

Unveiling the Implicit Toxicity in Large Language Models

EMNLP 2023long main

The open-endedness of large language models (LLMs) combined with their impressive capabilities may lead to new safety issues when being exploited for malicious use. While recent studies primarily focus on probing toxic outputs that can be easily detected with existing toxicity classifiers, we show t…

Cited by 0SourcecodeScholar
2022

Constructing Highly Inductive Contexts for Dialogue Safety through Controllable Reverse Generation

EMNLP 2022finding

Large pretrained language models can easily produce toxic or biased content, which is prohibitive for practical use. In order to detect such toxic generations, existing methods rely on templates, real-world data extraction, crowdsourcing workers or automatic generation to construct adversarial conte…

2022

Persona-Guided Planning for Controlling the Protagonist’s Persona in Story Generation

NAACL 2022long

Endowing the protagonist with a specific personality is essential for writing an engaging story. In this paper, we aim to control the protagonist’s persona in story generation, i.e., generating a story from a leading context and a persona description, where the protagonist should exhibit the specifi…

2022

Selecting Stickers in Open-Domain Dialogue through Multitask Learning

ACL 2022findings

With the increasing popularity of online chatting, stickers are becoming important in our online communication. Selecting appropriate stickers in open-domain dialogue requires a comprehensive understanding of both dialogues and stickers, as well as the relationship between the two types of modalitie…

2021

OpenMEVA: A Benchmark for Evaluating Open-ended Story Generation Metrics

ACL 2021long

Automatic metrics are essential for developing natural language generation (NLG) models, particularly for open-ended language generation tasks such as story generation. However, existing automatic metrics are observed to correlate poorly with human evaluation. The lack of standardized benchmark data…