MosaicLeaks - Privacy Leakage (Privacy-Aware Prompt): leaderboard

How much private enterprise information a deep-research agent leaks through its web queries on MosaicLeaks (Gurung et al., 2026): the share of rollouts in which a StepFun-3.5-Flash adversary that sees only the queries answers a private question or states a true private claim. Percent of 344 test tasks, mean of three runs with a planning prompt that warns against leaking private information; lower is better.

Metric: Privacy leakage (%; share of rollouts whose web queries let a StepFun-3.5-Flash adversary answer a private question or state a true private claim about the enterprise documents, mean of three runs; with the privacy-aware planning prompt; lower is better). Source: arxiv.org. Saturation forecast: Estimated already saturated. 6 models tracked.

Top models

#ModelScoreOverall rank
1Gemma 4 31B (IT)1.9#343
2Qwen 3 4B Instruct25.5#1660
3Qwen 3 8B27.2#1838
4GPT-OSS-20B34.8#1150
5Step 3.5 Flash39.9#508

No result here: #1 Claude Fable 5.2, #2 Gemini 4 Carbon, #5 Claude Opus 5.5.

Interactive version: theaggregate.ai/benchmark?slug=mosaicleaks-privacy-leakage-privacy-aware-prompt · How It Works · Data refreshed daily, snapshot 2026-11-12.