Large language models (LLMs) remain vulnerable to jailbreak attacks that elicit structured, credible misinformation. Existing benchmarks primarily track binary refusals, often overlooking the severity and exposure risk of the misinformation payload itself. In this work, we introduce Misinfo-Jailbreak Bench, a comprehensive framework that systematically maps diverse attack strategies to a claim-level scoring pipeline for precise risk quantification. Building on this diagnostic foundation, we propose Selective LoRA Ethical Surgery, a parameter-efficient defense mechanism. Instead of broad parameter updates, our approach identifies safety-relevant subspaces via contrastive representations to confine LoRA edits and employs inference-time gating to preserve benign capabilities. Experimental results on state-of-the-art models (e.g., Qwen2.5, Llama-4) demonstrate that our method reduces high-severity risk by 60-70% while limiting general capability degradation to less than 1%, offering a precise and minimally invasive paradigm for post-hoc alignment.

Long-context inference in large language models is limited by the linear memory growth of the key-value (KV) cache. Existing eviction methods typically retain tokens with high accumulated attention or remove semantic redundancy, but may discard low-frequency tokens that connect distant dependencies. We propose CentralKV, a training-free framework that models attention as a dynamic sparse causal graph. Its Stream-Influence algorithm updates token centrality online and preserves structurally important bridge tokens during KV compression. The attention graph is constructed directly from the attention operation without separate similarity computation. Experiments on LongBench show that CentralKV improves over H2O, SnapKV, and GraphKV under strict physical memory constraints, particularly on reasoning-intensive tasks, with minimal latency overhead.