Alignment Collapse Under KV Cache Quantization: Diagnosis and Mitigation

Evidence card

Claim

Low-bit KV cache quantization can degrade refusal/alignment behavior while conventional metrics remain stable in tested settings.

Evidence level

Emerging evidence

Source

https://arxiv.org/abs/2606.09864

Publication date

2026-06-01

Authors or institution

Bruce Changlong Xu, Adarsh Kumarappan, Mu Zhou

System tested

Eleven instruction-tuned models and multiple safety benchmarks as reported.

Limitations

Very recent preprint; production applicability depends on quantizer, model, deployment, and mitigations.

What the evidence does show

Low-bit KV cache quantization can degrade refusal/alignment behavior while conventional metrics remain stable in tested settings.

What the evidence does not show

That every KV cache optimization produces the same failure mode.

Date last reviewed in UTC

2026-06-26T00:00:00Z