Capture the Flag (Internal)

GPT-5.6 Sol 97.1% leads since Jun 2026 Only in system cards

Agents solve 63 public CTF challenges chosen for low GPT-5.3-Codex solve rates, using a Linux box with security tools. Scored as task success rate.

OpenAI says this set is harder than and different from the CTF sets it reported before GPT-5.6.

Made by OpenAI Released Jun 2026 Capture-the-flag challenges Tasks kept private Last in a system card Aug 2026 Last model added Aug 2026

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.

Models scored in lab cards

System cards report it, from 1 lab

GPT-5.6 Sol leads with 97.1% among models released by Jul 2026

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.

Bars Table

The newest model with a score here came out in Jul 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:

1 GPT-5.6 Sol 97.1%
2 GPT-5.6 Luna 93.2%
3 GPT-5.6 Terra 91.8%

#	Model	Score	Date	Source
1	GPT-5.6 Sol	97.1%	Aug 2026	Model card
2	GPT-5.6 Luna	93.2%	Aug 2026	Model card
3	GPT-5.6 Terra	91.8%	Jun 2026	Model card

Number one over time

Lab claims count from the day the card came out, independent runs from the model’s release.

OpenAI

Lab claims Passed 85% in Jun 2026, by GPT-5.6 Sol

GPT-5.6 Sol 97.1%

The best score passed 85% in Jun 2026

All the scores we have, one dot each, so a model tested at several settings appears more than once.

Reported by the lab in its model card Best so far

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.

8 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
6 Aug 2026	GPT-5.6 Sol system card addendum	97.1	Capture the Flag (CTF) Challenges, 63 challenges, pass@12, representative checkpoint, printed chart label (Figure 7, 7.1.2.1.1)	Cyber risk
6 Aug 2026	GPT-5.6 Luna system card addendum	93.2	Capture the Flag (CTF) Challenges, 63 challenges, pass@12, representative checkpoint, printed chart label (Figure 7, 7.1.2.1.1)	Cyber risk
9 Jul 2026	GPT-5.6 Terra system card	91.8	Capture-the-Flags challenge tasks (Internal), 63 challenges, pass@1, printed chart label (Figure 30, 9.1.2.1.1)	Cyber risk
9 Jul 2026	GPT-5.6 Sol system card	96.7	Capture-the-Flags challenge tasks (Internal), 63 challenges, pass@1, printed chart label (Figure 30, 9.1.2.1.1)	Cyber risk
9 Jul 2026	GPT-5.6 Luna system card	85.2	Capture-the-Flags challenge tasks (Internal), 63 challenges, pass@1, printed chart label (Figure 30, 9.1.2.1.1)	Cyber risk
25 Jun 2026	GPT-5.6 Terra system card	91.8	Capture-the-Flags challenge tasks (Internal), 63 challenges, pass@1, printed chart label (Figure 30, 9.1.2.1.1)	Cyber risk
25 Jun 2026	GPT-5.6 Sol system card	96.7	Capture-the-Flags challenge tasks (Internal), 63 challenges, pass@1, printed chart label (Figure 30, 9.1.2.1.1)	Cyber risk
25 Jun 2026	GPT-5.6 Luna system card	85.2	Capture-the-Flags challenge tasks (Internal), 63 challenges, pass@1, printed chart label (Figure 30, 9.1.2.1.1)	Cyber risk

GPT-5.6 Sol leads with 97.1% among models released by Jul 2026

Number one over time

The best score passed 85% in Jun 2026

Labs report it only in system cards

8 system cards report it, from 1 lab

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