freedomResearch notes on safety-removed models: mechanisms, defenses, measurement.

Last reviewed 2026-11-06

Defenses against safety removal

Weight-level defenses (model publisher side)

Defense Idea Status
Safety pretraining (arXiv 2510.02768) Put refusal behaviour into pretraining data so no single post-training direction carries it Research; granular study shows partial resistance
Extended-refusal fine-tuning (arXiv 2505.19056) Make refusals long-form and distributed across many directions Research
Decoy Direction Optimization (arXiv 2609.16204) Post-hoc: plant decoy refusal directions so ablation tooling removes the decoy and leaves the real one 2026 research
Fool's Gold (arXiv 2608.17202) Defensive deception against safety-removal attacks on open weights 2026 research
Tamper-resistant training (TAR and successors) Make fine-tuning away from safety expensive in compute Broken within months each cycle
Not releasing weights The only defense that fully holds A policy question, see 03-security-implications.md

Assessment: every published weight-level defense has been circumvented within months. The working assumption for a defender is that a safety-removed variant of every open-weight model exists the week it ships.

Boundary-level defenses (deployer side)

These are the controls that actually hold, because they do not depend on the model.

Control Notes
Sandbox: no network, no home directory, scratch filesystem Our sandboxed coding harness and overnight runner already do this
Explicit routing, no fallback chains A fallback fires on GPU contention, not on intent. Our LiteLLM config enforces this for abliterated routes
Never unattended No cron, no auto-retry into a safety-removed route
Tool allow-lists with approval on destructive actions The model's judgment about destructive actions is exactly what ablation weakens
Input classifier for prompt injection protectai/deberta-v3-base-prompt-injection-v2 is cached locally; useful, not sufficient
Output policy engine before side effects Regex plus a stock-model judge on anything that leaves the sandbox
Egress logging Everything the model sends out is recorded

Detection: is a served model safety-removed?

Open question worth a project of its own. Signals in the literature and our notes: - Near-zero over-refusal on XSTest-style benign-borderline prompts (stock models refuse 5 to 25 % of those; ablated ones refuse roughly none). - Elevated KL from the published base on harmless prompts. - Verbosity and sycophancy shifts. - Hash or fingerprint mismatch against the publisher's weights (only works for self-hosted weights you can inspect). A fingerprinting harness is a candidate task in tasks/.

Sources

arXiv 2510.02768, 2505.19056, 2609.16204, 2608.17202 · International AI Safety Report 2026 (arXiv 2602.21012) · dev.to mech_app_ai "Abliterated Models in Production" (2026) · a10networks.com model-abliteration-ai-safety