Expected Harm: Rethinking Safety Evaluation of (Mis)Aligned LLMs
Organizations: National Taiwan University, Taipei, Taiwan · Independent Researcher
Abstract
Current evaluations of LLM safety predominantly rely on severity-based taxonomies to assess the harmfulness of models' responses to malicious queries. We argue that this formulation requires re-examination as it implicitly equates model output with realized harm while neglecting Execution Likelihood-the conditional probability of a threat being realized by a real-world actor given a model's response. In this work, we introduce Expected Harm, a metric that weights the severity of a jailbreak by its execution likelihood, modeled as a function of execution cost. Through empirical analysis of state-of-the-art models, we reveal a systematic Inverse Risk Calibration: models disproportionately exhibit stronger refusal behaviors for low-likelihood (high-cost) threats while remaining vulnerable to high-likelihood (low-cost) queries. Mechanistically, we first provide an analysis using linear probing, revealing that while refusal mechanisms linearly separate queries by severity, they do not use execution likelihood as an indicator for refusal. Then, we use Olmo-3's open-source staged checkpoints to trace the root cause of miscalibration to the Supervised Fine Tuning (SFT) training data distribution (82.8% of safety examples at cost levels 0-1) and show that cost representations are weak from the SFT stage onward. Finally, we demonstrate that this miscalibration creates a vulnerability: by exploiting this property, we increase the attack success rate of existing jailbreaks by up to .
Figures & tables
| Checkpoint | Severity | Cost | Severity Spread | Cost Spread |
|---|---|---|---|---|
| Stage 0 - Base | 0.086 | -0.850 | 0.099 | 0.139 |
| Stage 1 - SFT | 0.679 | 0.493 | 0.303 | 0.125 |
| Stage 2 - DPO | 0.671 | 0.507 | 0.351 | 0.120 |
| Stage 3 - RLVR | 0.707 | 0.464 | 0.343 | 0.124 |
| Clean | GCG | Roleplay | Many Shot | AutoDAN | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Method | ASR | UN | ASR | UN | ASR | UN | ASR | UN | ASR | UN |
| Original | 0.0917 | 0.1854 | 0.2250 | 0.2000 | 0.0646 | 0.0541 | 0.0563 | 0.0333 | 0.1459 | 0.2479 |
| + Unrestricted | 0.1896 | 0.5209 | 0.2875 | 0.5146 | 0.1000 | 0.3313 | 0.0729 | 0.1437 | 0.2021 | 0.4416 |
| + Monitoring | 0.2167 | 0.5167 | 0.3063 | 0.5834 | 0.1916 | 0.5146 | 0.0917 | 0.1729 | 0.2438 | 0.4479 |
| + Cost | 0.2291 | 0.6042 | 0.3291 | 0.5854 | 0.1354 | 0.4708 | 0.1542 | 0.1875 | 0.2625 | 0.5542 |
| + Monitor + Cost | 0.2833 | 0.6250 | 0.3563 | 0.6167 | 0.2083 | 0.4791 | 0.1979 | 0.1562 | 0.2646 | 0.5333 |
| Decomposer | Method | Severity (Subtask Avg.) | Severity (Max per Task) | Cost (Subtask Avg.) | Cost (Max per Task) | # Subtasks per Task |
|---|---|---|---|---|---|---|
| None | Original | 2.18 | 2.18 | 1.41 | 1.41 | 1.00 |
| Daredevil-8B | + Unrestricted | 0.62 | 1.38 | 0.56 | 1.08 | 7.52 |
| + Monitoring | 0.70 | 1.29 | 0.60 | 1.08 | 5.37 | |
| + Cost | 0.69 | 1.52 | 0.52 | 1.18 | 6.16 | |
| + Monitor + Cost | 0.38 | 0.86 | 0.32 | 0.78 | 5.78 | |
| Hermes 3-70B | + Unrestricted | 0.86 | 1.64 | 0.63 | 1.13 | 6.19 |
Appendix figures & tables13 assets
Supplementary material from the paper’s appendix.
Appendix
| Model | Acc. | Off-by-1 | MAE |
|---|---|---|---|
| MiMo-V2 Flash | 70.6 | 96.1 | 0.37 |
| gpt-oss-120b | 68.0 | 96.0 | 0.36 |
| Gemini 2.5 Flash | 63.5 | 94.2 | 0.46 |
| Qwen3-30B | 53.8 | 90.4 | 0.60 |
| GPT-4o Mini | 42.3 | 92.3 | 0.69 |
| Model | DA | CoT (Std N=10) |
|---|---|---|
| OpenAI gpt-oss-120b | 72.95 | 65.48 (33.54) |
| + Majority vote | 85.71 | 84.62 |
| Xiaomi MiMo-v2-Flash | 26.87 | 79.93 (1.57) |
| + Majority vote | 22.03 | 84.72 |
| OpenAI GPT-4o-mini | 34.10 | 71.03 (1.57) |
| + Majority vote | 33.06 | 72.48 |
| AdvBench | HarmBench | SorryBench | StrongREJECT | |||||
|---|---|---|---|---|---|---|---|---|
| Method | ASR | Usefulness | ASR | Usefulness | ASR | Usefulness | ASR | Usefulness |
| Clean | 0.2750 | 0.0500 | 0.0000 | 0.3583 | 0.0250 | 0.1917 | 0.0667 | 0.1417 |
| +Decomp. (unrestricted) | 0.3417 | 0.5667 | 0.2167 | 0.4750 | 0.0667 | 0.4750 | 0.1333 | 0.5667 |
| +Decomp. (monitor) | 0.3833 | 0.5083 | 0.2333 | 0.5250 | 0.0583 | 0.4750 | 0.1917 | 0.5583 |
| +Decomp. (cost) | 0.3583 | 0.6333 | 0.2833 | 0.5250 | 0.0750 | 0.6167 | 0.2000 | 0.6417 |
| +Decomp. (cost + monitor) | 0.4667 | 0.7333 | 0.3833 | 0.6000 | 0.0667 | 0.4750 | 0.2167 | 0.6917 |
| AdvBench | HarmBench | SorryBench | StrongREJECT | |||||
|---|---|---|---|---|---|---|---|---|
| Method | ASR | Usefulness | ASR | Usefulness | ASR | Usefulness | ASR | Usefulness |
| Clean | 0.0000 | 0.0000 | 0.0083 | 0.0333 | 0.0167 | 0.0417 | 0.0083 | 0.0167 |
| +Decomp. (unrestricted) | 0.0917 | 0.2250 | 0.0917 | 0.2167 | 0.0250 | 0.2750 | 0.1833 | 0.3750 |
| +Decomp. (monitor) | 0.1333 | 0.4417 | 0.1250 | 0.3000 | 0.0500 | 0.3250 | 0.2000 | 0.4500 |
| +Decomp. (cost) | 0.0167 | 0.3167 | 0.1750 | 0.3667 | 0.0833 | 0.3250 | 0.1417 | 0.3667 |
| +Decomp. (cost + monitor) | 0.4750 | 0.0000 | 0.2167 | 0.3750 | 0.0583 | 0.3333 | 0.2083 | 0.4333 |
| Qwen3Guard-Gen-8B | Llama-Guard-3-8B | |||
| Method | Subtask | Task | Subtask | Task |
| original | 0.02 | 0.02 | 0.05 | 0.05 |
| Decomp. (unrestricted) | 0.76 | 0.36 | 0.82 | 0.45 |
| Decomp. (monitor) | 0.79 | 0.52 | 0.88 | 0.67 |
| Decomp. (cost) | 0.76 | 0.35 | 0.85 | 0.48 |
| Decomp. (cost + monitor) | 0.91 | 0.72 | 0.96 | 0.84 |
| Slice | High severity, low cost | Share of slice | Share of high severity | High cost | |
|---|---|---|---|---|---|
| SorryBench | 352 | 24 | 6.8% | 24.5% | 66 (18.8%) |
| AdvBench | 498 | 36 | 7.2% | 16.1% | 187 (37.6%) |
| HarmBench | 84 | 2 | 2.4% | 6.1% | 34 (40.5%) |
| StrongREJECT | 298 | 27 | 9.1% | 28.7% | 51 (17.1%) |
| WildChat-4.8M (flagged) | 3,130 | 588 | 18.8% | 80.8% | 85 (2.7%) |
| LMSYS-Chat-1M (flagged) | 11,163 | 4,352 | 39.0% | 81.5% | 702 (6.3%) |
| Severity | Cost 0 | Cost 1 | Cost 2 | Cost 3 |
|---|---|---|---|---|
| 1 | 40.0 (15) | 24.3 (70) | 18.8 (16) | – |
| 2 | 40.0 (15) | 14.6 (48) | 22.2 (9) | 10.0 (11) |
| 3 | 37.5 (8) | 7.6 (79) | 20.0 (25) | 7.7 (13) |
| 4 | – | 4.1 (74) | 0.0 (15) | 0.0 (16) |
| Severity | Cost 0 | Cost 1 | Cost 2 | Cost 3 |
|---|---|---|---|---|
| 1 | 39.1 (64) | 11.6 (783) | – | – |
| 2 | 54.5 (11) | 21.8 (1,112) | 13.2 (201) | – |
| 3 | 42.9 (17) | 7.2 (677) | 8.4 (135) | 5.6 (90) |
| 4 | 41.7 (12) | 4.6 (777) | 6.6 (61) | 1.0 (102) |
| Condition | |
|---|---|
| No safety data | |
| Natural safety SFT | |
| Strengthened cost–severity correlation | |
| Decorrelated, balanced continued SFT |
| Contrast | Clean | GCG | Roleplay | Many Shot | AutoDAN | Pooled |
|---|---|---|---|---|---|---|
| Mon Unres | .027 (.297) | .019 (.525) | .092 ( .001) | .019 (.291) | .042 (.121) | .040 ( .001) |
| Cost Unres | .040 (.132) | .042 (.162) | .035 (.089) | .081 ( .001) | .060 (.027) | .052 ( .001) |
| Mon+Cost Unres | .094 ( .001) | .069 (.023) | .108 ( .001) | .125 ( .001) | .062 (.022) | .092 ( .001) |
| Cost Mon | .012 (.642) | .023 (.446) | (.018) | .063 (.003) | .019 (.504) | .012 (.309) |
| Mon+Cost Mon | .067 (.017) | .050 (.100) | .017 (.519) | .106 ( .001) | .021 (.459) | .052 ( .001) |
| Mon+Cost Cost | .054 (.055) | .027 (.377) | .073 (.003) | .044 (.075) | .002 (.942) | .040 (.001) |
Language Model Safety Evaluation
Language model safety evaluation measures harmful behavior, refusal, robustness, and over-refusal across realistic prompts, users, and deployment settings.
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