Cybench
40 professional capture-the-flag tasks from four competitions. Agent must recover the flag, with optional subtasks.
40 professional CTF tasks from four competitions, each split into subtasks for partial credit. Agents work in a Kali Linux environment. The board mixes HAL leaderboard runs with lab system-card scores on 35 to 39 task subsets. Anthropic reports it near saturation. The makers point readers to their later BountyBench.
In the authors’ words
Language Model (LM) agents for cybersecurity that are capable of autonomously identifying vulnerabilities and executing exploits have potential to cause real-world impact. Policymakers, model providers, and researchers in the AI and cybersecurity communities are interested in quantifying the capabilities of such agents to help mitigate cyberrisk and investigate opportunities for penetration testing. Toward that end, we introduce Cybench, a framework for specifying cybersecurity tasks and evaluating agents on those tasks. We include 40 professional-level Capture the Flag (CTF) tasks from 4 distinct CTF competitions, chosen to be recent, meaningful, and spanning a wide range of difficulties. Each task includes its own description, starter files, and is initialized in an environment where an agent can execute commands and observe outputs. Since many tasks are beyond the capabilities of existing LM agents, we introduce subtasks for each task, which break down a task into intermediary steps for a more detailed evaluation. To evaluate agent capabilities, we construct a cybersecurity agent and evaluate 8 models: GPT-4o, OpenAI o1-preview, Claude 3 Opus, Claude 3.5 Sonnet, Mixtral 8x22b Instruct, Gemini 1.5 Pro, Llama 3 70B Chat, and Llama 3.1 405B Instruct. For the top performing models (GPT-4o and Claude 3.5 Sonnet), we further investigate performance across 4 agent scaffolds (structed bash, action-only, pseudoterminal, and web search). Without subtask guidance, agents leveraging Claude 3.5 Sonnet, GPT-4o, OpenAI o1-preview, and Claude 3 Opus successfully solved complete tasks that took human teams up to 11 minutes to solve. In comparison, the most difficult task took human teams 24 hours and 54 minutes to solve. All code and data are publicly available at https://cybench.github.io.
- Level
- Expert Specialists with years of training, often over hours of work
- Scored
- Checked automatically A program checks the result against an answer key, unit tests or the expected final state.
- Answers
- Agent task Many steps in a terminal, browser, desktop, app, game or robot.
Claude Mythos Preview leads with 100% among models released by Apr 2026
Best score per model from the benchmark's own leaderboard, read on 2 Nov 2026. Where a model ran with several settings or harnesses, we keep its best.
The newest model with a score here came out in Apr 2026, and nobody has tested a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- GPT-6 Astra
- Claude Opus 5.5
- GPT-6.1 Terra
- GPT-6.1 Sol
- and 16 more
- 100.0 Claude Mythos Preview
- 96.0 Claude Opus 4.7
- 93.0 Claude Opus 4.6
- 82.0 Claude Opus 4.5
- 65.4
Muse Spark
- 60.0 Claude Sonnet 4.5
- 43.0 Grok 4
- 42.0 Claude Opus 4.1
- 39.0 Grok 4.1
- 38.0 Claude Opus 4
- 35.0 Claude Sonnet 4
- 30.0 Grok 4 Fast
- 22.5 o3-mini
- 20.0 Claude 3.7 Sonnet
- 17.5 Claude 3.5 Sonnet
- 17.5 GPT-4.5
- 12.5 GPT-4o
- 10.0 Claude 3 Opus
- 10.0 o1-mini
- 10.0 o1-preview
- 7.50
Mixtral 8x22B
- 7.50
Gemini 1.5 Pro
- 7.50
Llama 3.1-405B
- 5.00
Llama 3-70B
- 1 Claude Mythos Preview 35 of 40 tasks 100%
- 2 Claude Opus 4.7 35 of 40 tasks 96%
- 3 Claude Opus 4.6 37 of 40 tasks 93%
- 4 Claude Opus 4.5 39 of 40 tasks 82%
- 5
Muse Spark 65.4%
- 6 Claude Sonnet 4.5 39 of 40 tasks 60%
- 7 Grok 4 43%
- 8 Claude Opus 4.1 39 of 40 tasks 42%
- 9 Grok 4.1 39%
- 10 Claude Opus 4 37 of 40 tasks 38%
- 11 Claude Sonnet 4 37 of 40 tasks 35%
- 12 Grok 4 Fast 30%
- 13 o3-mini 22.5%
- 14 Claude 3.7 Sonnet 20%
- 15 Claude 3.5 Sonnet 17.5%
- 16 GPT-4.5 17.5%
- 17 GPT-4o May 2024 12.5%
- 18 Claude 3 Opus 10%
- 19 o1-mini 10%
- 20 o1-preview 10%
- 21
Mixtral 8x22B 7.50%
- 22
Gemini 1.5 Pro May 2024 7.50%
- 23
Llama 3.1-405B 7.50%
- 24
Llama 3-70B 5.00%
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Claude Mythos Preview | 100% | 35 of 40 tasks | Apr 2026 | Official leaderboard |
| 2 | Claude Opus 4.7 | 96% | 35 of 40 tasks | Apr 2026 | Official leaderboard |
| 3 | Claude Opus 4.6 | 93% | 37 of 40 tasks | Feb 2026 | Official leaderboard |
| 4 | Claude Opus 4.5 | 82% | 39 of 40 tasks | Nov 2025 | Official leaderboard |
| 5 | | 65.4% | Apr 2026 | Official leaderboard | |
| 6 | Claude Sonnet 4.5 | 60% | 39 of 40 tasks | Sep 2025 | Official leaderboard |
| 7 | Grok 4 | 43% | Jul 2025 | Official leaderboard | |
| 8 | Claude Opus 4.1 | 42% | 39 of 40 tasks | Aug 2025 | Official leaderboard |
| 9 | Grok 4.1 | 39% | Nov 2025 | Official leaderboard | |
| 10 | Claude Opus 4 | 38% | 37 of 40 tasks | May 2025 | Official leaderboard |
| 11 | Claude Sonnet 4 | 35% | 37 of 40 tasks | May 2025 | Official leaderboard |
| 12 | Grok 4 Fast | 30% | Sep 2025 | Official leaderboard | |
| 13 | o3-mini | 22.5% | Jan 2025 | Official leaderboard | |
| 14 | Claude 3.7 Sonnet | 20% | Feb 2025 | Official leaderboard | |
| 15 | Claude 3.5 Sonnet | 17.5% | Jun 2024 | Official leaderboard | |
| 16 | GPT-4.5 | 17.5% | Feb 2025 | Official leaderboard | |
| 17 | GPT-4o May 2024 | 12.5% | May 2024 | Official leaderboard | |
| 18 | Claude 3 Opus | 10% | Feb 2024 | Official leaderboard | |
| 19 | o1-mini | 10% | Sep 2024 | Official leaderboard | |
| 20 | o1-preview | 10% | Sep 2024 | Official leaderboard | |
| 21 | | 7.50% | Apr 2024 | Official leaderboard | |
| 22 | | 7.50% | May 2024 | Official leaderboard | |
| 23 | | 7.50% | Jul 2024 | Official leaderboard | |
| 24 | | 5.00% | Apr 2024 | Official leaderboard |
Epoch AI has scores for 21 models. Labs report scores for 17 models in their cards. We plot every source in the charts below.
8 models have held number one since its release in Aug 2024
Lab claims count from the day the card came out, independent runs from the model’s release. We draw one row each for the benchmark’s own leaderboard, Epoch AI’s runs and what labs claim in their cards.
The best score passed 85% in Feb 2026
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Labs report it only in system cards
We read the headline results of 479 launch posts from 51 labs, and none of them list this benchmark. Some system cards do, below.
18 system cards report it, from 3 labs
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 |
|---|---|---|---|---|
| 9 Jul 2026 | | 92.9 | Cybench pass@1, unguided, 40 challenges, unmitigated Muse Spark 1.1 (Table 1, Table 3). pass@10 = 97.0 | Cyber risk |
| 12 Jun 2026 | | 65.4 | CyBench pass@1, all 40 challenges (Table 1, Table 7). pass@10 79.0, pass@30 82.2 | Cyber risk |
| 16 Apr 2026 | Claude Opus 4.7 system card | 96 | Cybench, pass@1 96% on a 35-challenge subset, 10 trials per challenge, no thinking with think tool (3.3.1) | Cyber risk |
| 7 Apr 2026 | Claude Mythos Preview system card | 100 | Cybench, pass@1 100% on a 35-challenge subset, 10 trials per challenge, no thinking with think tool (3.3.1) | Cyber risk |
| 17 Feb 2026 | Claude Sonnet 4.6 system card | 90 | Cybench, average pass@1 0.90 on the RSP subset of 37 challenges; pass@30 100 (6.4.7) | Cyber risk |
| 5 Feb 2026 | Claude Opus 4.6 system card | 93 | Cybench, average pass@1 0.93 on the RSP subset, 3 of 40 not run; 100% with 30 trials (8.4.7, Figure 8.4.7.A) | Cyber risk |
| 24 Nov 2025 | Claude Opus 4.5 system card | 82 | Cybench, average pass@1 0.82 on the subset of challenges used for RSP evaluations, 1 of 40 not run (7.4.7, Figure 7.4.6.A) | Cyber risk |
| 17 Nov 2025 | Grok 4.1 model card | 39 | CyBench, unguided success rate 0.39, Grok 4.1 Thinking (Table 4) | Cyber risk |
| 15 Oct 2025 | Claude Haiku 4.5 system card | 46.9 | Cybench 32-challenge subset, 15/32 solved at least once in 30 attempts, pass@30 (6.4) | Cyber risk |
| 8 Oct 2025 | | 25 | Cybench unguided, pass@10, 10 of 40 CTFs. Easy 50.0, Medium 11.1, Hard 12.5 (Tables 3 and 4) | Cyber risk |
| 29 Sep 2025 | Claude Sonnet 4.5 system card | Cybench, 37 of 40 challenges, mean pass@1 by difficulty and category and pass@k curve, charts without printed values. Text says success above 80% at 30 trials (5.2.2, Figures 5.2.2.A and 5.2.2.B) | Cyber risk | |
| 19 Sep 2025 | Grok 4 Fast model card | 30 | CyBench, unguided success rate 30.0 (Table 3) | Cyber risk |
| 26 Aug 2025 | grok-code-fast-1 model card | 22.5 | CyBench, unguided success rate 22.5 (Table 3) | Cyber risk |
| 20 Aug 2025 | Grok 4 model card | 43 | CyBench, unguided success rate 0.43, Grok 4 API, Inspect harness (Table 3) | Cyber risk |
| 5 Aug 2025 | Claude Opus 4.1 system card addendum | 51.4 | Cybench 35-challenge subset, 18/35 solved, pass@30 (6.5.1) | Cyber risk |
| 22 May 2025 | Claude Sonnet 4 system card | 56.4 | Cybench, 22/39 challenges solved, pass@30 (7.4.7) | Cyber risk |
| 22 May 2025 | Claude Opus 4 system card | 56.4 | Cybench, 22/39 challenges solved, pass@30 (7.4.7) | Cyber risk |
| 24 Feb 2025 | Claude 3.7 Sonnet system card | 44.1 | Cybench, succeeded at least once on 15/34 challenges tested (pass@k over up to 30 trials). Best-of-k curve on a 30-challenge subset has no printed values (7.3.2, Figure 25) | Cyber risk |
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