StrongREJECT v2 (Meta)
Muse Spark 1.1 0.50% leads since Jul 2026 In use Models face a cascade of jailbreak attacks on disallowed behaviors adapted from StrongREJECT plus internal ones. Reports attack success rate.
Meta variant of public StrongREJECT with internally curated behaviors and a multi-turn LLM attacker.
- Level
- Expert Specialists with years of training, often over hours of work
- Scored
- Graded by a model A language model scores each response, usually against a rubric.
- Answers
- Open-ended Free-form text, documents, designs or media judged as a whole.
3 models share the top score of 0.50%
Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.
- 1 Muse Spark 1.1 0.50%
- 2 Muse Spark Open 0.50%
- 3 Muse Spark 1.3 0.50%
- 4 Muse Spark 44.6%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Muse Spark 1.1 | 0.50% | Jul 2026 | Model card | |
| 2 | Muse Spark Open | 0.50% | Oct 2026 | Model card | |
| 3 | Muse Spark 1.3 | 0.50% | Oct 2026 | Model card | |
| 4 | Muse Spark | 44.6% | Jun 2026 | Model card |
2 models have held number one since 2023
Lab claims count from the day the card came out, independent runs from the model’s release.
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
One lab put it in a launch post in the last six months
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| 15 Oct 2026 | Muse Spark Open | 0.5 | StrongREJECT v2 (adaptive), lower is better |
3 system cards report it, from 1 lab
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| 23 Oct 2026 | Muse Spark 1.3 system card | 0.5 | StrongREJECT v2 ASR averaged over single-turn and multi-turn, Muse Spark 1.3 (API) max (Table 2, Figure 21) | Robustness |
| 9 Jul 2026 | Muse Spark 1.1 system card | 0.5 | StrongREJECT v2 ASR (Table 2 scorecard, Figure 24) | Robustness |
| 12 Jun 2026 | Muse Spark system card | 44.6 | StrongREJECT v2 ASR at end of cascaded attack pipeline, Muse Spark (Table 2, Figure 27) | Robustness |
More in Safety and alignment
- FORTRESS In use Paired adversarial and benign national-security misuse prompts. Rubric-graded risk score on adversarial and over-refusal score on benign prompts. Claude Opus 5.5 5.78%
- StrongREJECT In use Forbidden-prompt jailbreak benchmark with a rubric grader that scores how useful a non-refusal actually is.
Inkling 98.6% - AgentDojo In use Agents do tool-use tasks while tools and data carry prompt injections. Attack success rate counts hijacked runs. Grok 4 Fast 0%
- MASK In use Measures whether a model contradicts its own elicited beliefs under pressure to lie. Honesty separated from accuracy. Muse Spark Open 98.1%
- Gray Swan IPI Arena benchmark In use Indirect prompt-injection attacks from public red-teaming competitions replayed on tool, coding and browser agents. Attack success rate at k attempts. GPT-6 Astra 8.50%
- Agentic misalignment suite (Anthropic) In use Agents in simulated company settings face threats or goal conflicts that invite blackmail, leaking or sabotage. Score is the misaligned action rate. Claude Sonnet 4.5 0%