Sep 3 – 4, 2025
Hörsaalgebäude, Campus Poppelsdorf, Universität Bonn
Europe/Berlin timezone

In-Training Defenses against Emergent Misalignment in Language Models

NLP.3.2
Sep 4, 2025, 1:00 PM
1h 15m
Open Space (first floor)

Open Space (first floor)

Board: NLP.3
Poster Natural Language Processing Poster Session

Speaker

David Kaczér (University of Bonn)

Description

Fine-tuning lets practitioners repurpose aligned large language models (LLMs) for new domains, yet recent work reveals emergent misalignment (EMA): Even a small, domain-specific fine-tune can induce harmful behaviors far outside the target domain. Even in the case where model weights are hidden behind a fine-tuning API, this gives attackers inadvertent access to a broadly misaligned model in a way that can be hard to detect from the fine-tuning data alone. We present the first systematic study of in-training safeguards against EMA that are practical for providers who expose fine-tuning via an API. We investigate four training regularization interventions: (i) KL-divergence regularization toward a safe reference model, (ii) $\ell^2$ distance in feature space, (iii) projecting onto a safe subspace (SafeLoRA), and (iv) interleaving of a small amount of safe training examples from a general instruct-tuning dataset. We first evaluate the methods’ emergent misalignment effect across four malicious, EMA-inducing tasks. Second, we assess the methods’ impacts on benign tasks. We conclude with a discussion of open questions in emergent misalignment research.

Author

David Kaczér (University of Bonn)

Co-authors

Clemens Vetter (University of Bonn) Dr Florian Mai (University of Bonn) Prof. Lucie Flek (University of Bonn) Magnus Jørgenvåg (University of Bonn)

Presentation materials