OBLITERATUS/Qwen3.8-27B-OBLITERATED
OBLITERATUS/Qwen3.8-27B-OBLITERATED is an "abliterated" (safety-guardrail-removed) fine-tune of Alibaba's Qwen3.8-27B, built by Pliny the Prompter using the OBLITERATUS ablation suite. Its V3 recipe blends two refusal-direction-removal techniques — aggressive SVD projection and LEACE — in iterative rounds with a targeted refusal-corpus, eliminating both hard refusals and softer "safety lecture" deflections while costing only -2.1pp MMLU versus stock. The model card frames it explicitly for alignment researchers, red-teamers, and AI safety evaluators needing an unrestricted baseline to test post-training safety against weight-space attacks.
What it is
OBLITERATUS/Qwen3.8-27B-OBLITERATED — the concrete detail the summary omits is scale and accessibility. The page reports 1,235,942 downloads last month and ships one-line local-run commands for every major runtime (Ollama, llama.cpp, vLLM, LM Studio, Docker). This is not a niche research artifact; it is a mass-distributed, guardrail-stripped 27B model runnable on consumer hardware with a single command.
How it works — the actual recipe parameters
The summary names SVD + LEACE; the page gives the exact surgery chain to reproduce or fingerprint:
- V1: stock → 5 rounds iterative SVD (5 directions, low reg) → 0% refuse, -6pp MMLU
- V2: V1 chain → blend of Surgery A (aggressive SVD, 3 dirs, reg 0.08) + Surgery B (LEACE, 3 dirs, reg 0.06) at 60% B / 40% A weight-space LERP, restore MTP+vision → -0.3pp MMLU
- V3: V2 → refinement (2-dir SVD, reg 0.04) → targeted surgery (3-dir SVD, reg 0.01) → 50/50 blend → 0% refuse + 0% deflect, -2.1pp MMLU
MMLU cost is non-uniform: STEM takes -3.3pp, humanities only -1.0pp, while philosophy (+6pp) and European history (+4pp) improved. The author reads this as refusal directions overlapping structured-reasoning pathways.
What to do
For a red-teamer or evaluator wanting the unrestricted baseline, the page's own run commands:
ollama run hf.co/OBLITERATUS/Qwen3.8-27B-OBLITERATED:Q4_K_Mvllm serve "OBLITERATUS/Qwen3.8-27B-OBLITERATED"Two operational gotchas the model card flags:
- GGUF chat template prefills an empty thinking block so the model answers immediately — use the bundled template with
--jinjain llama.cpp, or the model's built-in template in Ollama/LM Studio. - Agent-harness loops (coding agents, pentest frameworks): load via Transformers with
enable_thinking=False,do_sample=False,repetition_penalty=1.15.
Full weights are ~54 GB bfloat16 (29 shards); Q4_K_M GGUF for local use. Apache 2.0, same as base.
Caveats
The author's own "liberation quality" scoring is manual audit, not a reproducible harness — they explicitly note regex refusal detectors miss soft deflections, so the "0% deflect" claim rests on human judgment over 1000+ prompts, unverifiable from the card. The MMLU figures use n=100 per subject (0-shot), a small sample. The page explicitly credits Pliny the Prompter and states the model "will comply with requests that stock Qwen3.8-27B would refuse" across restricted knowledge, security research, and red-team scenarios.
Organisations named here
- Pliny the Prompter
Technologies named here
- Qwen3.8-27B
- OBLITERATUS
- MLX / MLX LM
- llama.cpp
- vLLM
- Ollama
- Docker Model Runner
- Lemonade
- LM Studio
- Jan
- Unsloth Desktop
- Atomic Chat
- 🤗 Transformers
- lm-eval-harness
- Qwen
- Hugging Face
Techniques named here
- Abliteration
- SVD abliteration
- LEACE
- Complementary abliteration blending
- Iterative stacking / iterative refinement
- Targeted corpus surgery
- Honest/manual refusal-and-deflection scoring
Related in AI Security
