GPT-5.6-Cyber replaces ad hoc jailbreaking with a purpose-built exploit-development model built on GPT-5.6 Sol: a 400,000-token context window, agentic tools like hosted shell and computer use, and stronger exploit-chain results than its immediate predecessor. It is built for authorized red teams, not general developers.
GPT-5.6-Cyber, released by OpenAI in August 2026, is a cybersecurity-specialized fine-tune of GPT-5.6 Sol. It completed 95% of advanced exploit-development requests on OpenAI's internal Advanced Cybersecurity Completion Rate eval, versus 1.5% for standard Sol. Access is restricted to vetted partners through the new Daybreak Red program, not the general API.
Provider: OpenAI · Family: GPT-5.6
Context window: 400,000 tokens · Max output: 128,000
Input modalities: text, image, tool-calls · Output: text, tool-calls
About GPT-5.6-Cyber
OpenAI released GPT-5.6-Cyber on August 10, 2026 as a cybersecurity-specialized fine-tune of GPT-5.6 Sol, the fourth member of the GPT-5.6 lineup alongside Sol, Terra, and Luna, which reached general availability on July 9, 2026 after a limited preview from June 26, 2026. OpenAI has not disclosed whether the underlying architecture is dense or mixture-of-experts, nor a parameter count, for either GPT-5.6-Cyber or the Sol backbone it is built on. Its purpose is narrow: finding zero-days, building exploit chains, and validating vulnerabilities for vetted, authorized security work. OpenAI measures this with an internal evaluation called the Advanced Cybersecurity Completion Rate, and on it this model completed the large majority of advanced cyber requests it was tested against, including exploit-chain development, privilege escalation, and authentication bypass, a sharp jump over both its immediate predecessor and standard GPT-5.6 Sol running with its default safeguards (see the benchmark FAQ below for the exact figures). It also posted the best result in the GPT-5.6 line on ExploitGym, the evaluation that tests turning a known vulnerability into a working, arbitrary-code-execution exploit. The gains are not uniform: OpenAI's own system card describes the improvement on CVE-Bench, a benchmark the Sol backbone already scores 97.06% on, as comparatively modest. The model carries a 400,000-token context window and a 128,000-token maximum output, with standard-rate pricing covering most of that input space before an overage rate applies (see the pricing FAQ for the exact threshold). That is enough headroom to hold a full application codebase, a long CVE writeup, or a multi-stage exploit transcript in a single session without truncation. Input modalities are text and image; output is text only. It supports function calling, structured outputs, streaming, and prompt caching, plus a tool roster built for agentic security work: web search, file search, a code interpreter, a hosted shell, patch application, computer use, and MCP integration. Only the Responses API (v1/responses) exposes it; Chat Completions, Realtime, Assistants, Batch, and fine-tuning endpoints are all unavailable for this model, so teams integrating against those APIs elsewhere in the GPT-5.6 family need a separate integration path here. Pricing sits well above general-purpose GPT-5.6 Sol, reflecting both the output rate and the model's narrow, gated distribution; exact per-token rates and the overage structure are detailed in the pricing FAQ below. A vulnerability triage pass reading 50,000 tokens and writing a 10,000-token report costs roughly $1.38. A full exploit-chain session that fills the standard input allowance with a 60,000-token output runs about $7.90. A day of authorized pentest work spanning 1 million input tokens and 200,000 output tokens comes to roughly $27.50. Access runs only through OpenAI's Daybreak program, specifically the new Daybreak Red tier introduced alongside this model; the companion Daybreak Blue tier grants vetted defenders access to Sol without its default cyber guardrails, rather than to Cyber itself. Rate limits scale across five standard tiers, from 500 requests and 500,000 tokens per minute at the entry tier up to 15,000 requests and 40 million tokens per minute at the top tier. At launch, around 16 organizations held access: Accenture, IBM, Capgemini, Cognizant, EY, KPMG, PwC, NCC Group, and SpecterOps on the consulting and research side, and Palo Alto Networks, CrowdStrike, Cisco, Sophos, Akamai, Fortinet, and Cloudflare among security vendors. OpenAI classifies the model as High capability in cybersecurity under its Preparedness Framework, one tier below Critical; the system card states GPT-5.6 Sol and Terra "can find vulnerabilities and pieces of exploits" but were "unable to carry out autonomous, end-to-end attacks against hardened targets" in testing. The release is backed by more than 700,000 A100e GPU-hours of automated jailbreak search, an automated red-teaming model called GPT-Red, and third-party cyber capability evaluations from UK AISI and Irregular. Deployment monitoring blocks roughly ten times more activity than prior models, and Daybreak Red access itself requires identity verification, account security checks, and legal attestations before any credential is issued. The model fits a narrow case: penetration testers, vulnerability researchers, and red teams inside vetted Daybreak Red partner organizations doing exploit validation and responsible-disclosure work under contract. It is the wrong choice for general-purpose coding or chat, where GPT-5.6 Sol or Terra cost far less and need no approval process, and it is simply unreachable for anyone outside the partner list, however legitimate the use case. Knowledge cutoff is February 16, 2026. The model inherits Sol's training pipeline plus additional activation classifiers focused on sensitive domains, layered under a reduced-refusal configuration reserved for vetted Daybreak Red use. OpenAI's instruction hierarchy still enforces platform- and developer-level policy checks, and API deployments can set developer-configurable confirmation policies for high-risk actions rather than relying on one fixed refusal boundary. GPT-5.6-Cyber succeeds the previous generation of OpenAI's Cyber line and launched alongside the Daybreak Blue and Red tier split that same day, roughly a month after GPT-5.6 Sol's own general availability. How much the completion rate jumped in one model generation is why OpenAI chose to gate this variant behind a vetting program instead of shipping it broadly alongside Sol, Terra, and Luna.
Pricing
$12.50 per 1M input tokens, $75.00 per 1M output tokens, $1.25 per 1M cached input tokens. Requests beyond the 272,000-token input cap are billed at 2x the input rate and 1.5x the output rate for the overflow. No free tier, no self-serve signup; billing only begins once OpenAI approves Daybreak Red access.
Key Features
- Advanced Cybersecurity Completion Rate: Leads every model in the GPT-5.6 family on OpenAI's internal cyber-completion evaluation, a sharp jump over the prior Cyber generation (exact figures in the FAQ below).
- 128K-Token Output Ceiling With Automatic Overage: Outputs cap at 128,000 tokens per response, and requests that push past the standard input allowance are billed at a higher rate instead of failing outright.
- Agentic Security Toolset In One Session: Web search, file search, code execution, a hosted shell, patch application, and computer use are all callable from a single Responses API conversation.
- Daybreak Red Gated Access: Reachable only through OpenAI's Daybreak Red program after identity verification and a legal attestation, not via a standard API key.
- ExploitGym Leader: Turns known vulnerabilities into functioning exploits more reliably than any other model OpenAI has shipped in the GPT-5.6 line, per OpenAI's own ExploitGym results.
Pros
- Highest measured completion rate on OpenAI's internal cybersecurity evaluation of any GPT-5.6 variant, purpose-built to close the gap the safeguarded base model leaves open.
- Backed by more red-teaming investment than any prior GPT-5.6 release: large-scale automated adversarial search, a dedicated red-team model, and independent evaluation before launch.
- Context window large enough to hold an entire codebase or a multi-stage exploit transcript in one pass, without chunking large targets across sessions.
Cons
- Not self-serve: requires Daybreak Red approval, identity verification, and a legal attestation before any API key is issued.
- Only the Responses API is supported, so integrations built on Chat Completions, Realtime, Assistants, Batch, or fine-tuning do not carry over.
- Internal completion-rate gains are dramatic, but OpenAI's own system card describes the CVE-Bench improvement over the prior Cyber generation as modest, so the headline result does not generalize evenly.
Benchmarks
- advanced cybersecurity completion rate: 95
Frequently Asked Questions
How much does GPT-5.6-Cyber cost per 1M tokens?
Input runs $12.50 per 1M tokens and output runs $75.00 per 1M tokens, with cached input priced at $1.25 per 1M tokens. Once a request's input passes 272,000 tokens, the overflow is charged at double the input rate and 1.5 times the output rate. GPT-5.6-Cyber has no free tier, and billing only starts after OpenAI approves Daybreak Red access.
How does GPT-5.6-Cyber compare to GPT-5.5-Cyber on cybersecurity benchmarks?
GPT-5.6-Cyber posted a 95% score on the Advanced Cybersecurity Completion Rate, OpenAI's internal benchmark for exploit-development requests, well ahead of the 57.3% that GPT-5.5-Cyber managed on the same test. It also edges out that predecessor and standard GPT-5.6 Sol on ExploitGym, though CVE-Bench tells a different story: OpenAI's system card calls that particular gain modest rather than dramatic.
Is GPT-5.6-Cyber open source or proprietary?
GPT-5.6-Cyber is fully proprietary. OpenAI does not release its weights, and the model is reachable only through its own Responses API endpoint after Daybreak Red approval, not through Bedrock, Vertex, Azure, or any other third-party cloud.
Does GPT-5.6-Cyber train on the data submitted to it?
OpenAI's standard API policy applies: inputs and outputs are not used to train models by default. Given the sensitivity of the exploit and vulnerability data this model handles, Daybreak Red access additionally requires identity verification, account security controls, and a signed legal attestation before any credential is issued.
Who is GPT-5.6-Cyber best for, and who should avoid it?
It is built for vetted penetration testers, vulnerability researchers, and security vendors doing authorized exploit validation, the roughly 16 organizations approved for Daybreak Red at launch, including Palo Alto Networks, CrowdStrike, Accenture, and IBM. General developers, or any team without Daybreak Red approval, should use standard GPT-5.6 Sol or Terra instead, both cheaper and available without a vetting process.