Prompt injections that keep the answer on target still fooled every tested model, raising attack success by up to 35.8 percentage points
AspireAI community · arXiv preprint
Most prompt-injection benchmarks test attacks that throw away the user's request entirely, which is the easy case to catch. NTBench tests the harder one: injections that keep the response on topic but nudge it toward an incorrect or harmful answer. Built from legitimate tasks in existing datasets, the benchmark steers each model toward a reference-guided target, with separate tracks for wrong answers and for harmful ones, and then checks whether the injected deviation actually appears. Under a common budget of three attack executions per sample, seven models across ten language datasets and two agent benchmarks all did worse than against the conventional fixed-target baseline: attack success rose by 9.3 to 35.8 percentage points on the incorrect track and 1.7 to 17.3 points on the harmful track.
The practical lesson for anyone running an agent against untrusted content is that a model can resist an obvious takeover and still be steered into producing a confidently wrong answer.
Caveat: the benchmark measures the injected deviation's presence, and the base rate of deviations observed without injection is subtracted; results are single-benchmark-attack results, not a new attack method.
Read the story and explore more from the AspireAI community.
Two sparse-autoencoder analyses have resisted scaling: matching semantically similar features across layers, and compressing large feature circuits into interpretable supernodes. This paper argues both are the same underlying problem, estimating semantic distances between SAE features that sit on different activation manifolds. Its representation treats each feature not as a single decoder vector but as an activation-weighted distribution over the hidden states expressing it, projects those distributions into a shared reference space, and compares them with Wasserstein distance. The representation is proved invariant to activation rescaling and stable under perturbation, and recovers true matches under finite-sample margin conditions. Empirically it outperformed decoder-vector and LLM-based baselines and captured subtle functional distinctions between related features, and it compressed large feature circuits into interpretable supernodes automatically. The limitation is that this is interpretability tooling: the paper demonstrates better feature matching and circuit compression, not that downstream interpretability claims become more accurate.