GPT-6.2 Astra and Claude 5.5 Leaked in the Same Weekend
Less than a week after Gemini 4 Carbon took the top ranking, the next flagships from OpenAI and Anthropic leaked almost simultaneously: GPT-6.2 Astra quietly tested inside Codex, and Claude Mythos 5.5 plus Fable 5.5 exposed in Anthropic's own website source code. A claim-versus-evidence breakdown.
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This weekend the AI industry looked like a race with no starting gun. Gemini 4 Carbon had only just seized the global number one ranking, and within days, two of its rivals “lost” their next flagships almost on the same day: OpenAI with GPT-6.2 Astra, Anthropic with the Claude 5.5 series.
In my view, this is exactly where we should slow down. What is circulating right now is a leak, not an announcement. There is no model card, no pricing page, and no official release date from either lab. So this piece follows one simple rule: separate what is reported from what is proven.
The OpenAI side: GPT-6.1 skipped, straight to 6.2
According to an AIBase report carried by KuCoin, OpenAI skipped the planned GPT-6.1 release and instead upgraded a model that had been retrained for a month over safety-testing issues. The result is called GPT-6.2 Astra, and it has reportedly entered gray-scale testing in the Codex backend, handling nearly 20 percent of traffic.
The capability claims are not modest either. Compared with its predecessor, GPT-6.2 Astra is said to fix older weaknesses such as inaccurate reporting and uneven real-world performance, and thanks to a 28-day overhaul of the Codex architecture, it can allegedly launch subprocesses autonomously and work continuously for hours.
To me, that 20 percent traffic figure is the most interesting detail in the whole leak, if it is true. A gray-scale rollout that large is not a casual experiment; it is a lab validating a model under real production load. The problem is that this remains a third-party report about an internal system none of us can see. There is no way to verify it from the outside.
The Anthropic side: caught by its own source code
Anthropic’s story is more unusual, and honestly more entertaining. On November 1, an influencer named Chubby shared a screenshot of the source code of anthropic.com/claude/mythos, which openly referenced Claude Mythos 5.5. From the same leak, the 5.5 series reportedly has two variants built on the same foundation with opposite characters.
The first, Mythos 5.5, is described as a special security edition: available only to top cybersecurity and research institutions, and reportedly a professional model without safeguards. In reported testing, it allegedly exploited the Linux kernel and gained root privileges autonomously in 53 minutes, and can complete full mathematical papers on its own.
The second, Fable 5.5, is the general flagship: ultra-long context up to 1 million tokens, already listed in related cloud service catalogs, and claimed to sustain one to two hours of continuous work and generate complex 3D projects, such as a 3D version of Minecraft, from a single prompt.
Those two numbers, 53 minutes to root and 1 million tokens, are extremely marketable figures. That is precisely why I file them as leak claims, not facts. Even benchmark numbers from official launches deserve critical reading, let alone numbers arriving via source-code snippets and aggregator reports.
Why did both leak at once?
Some read the timing as strategy. ChainCatcher noted expectations that Anthropic’s official release window likely falls this week, around November 3 or 4, since the Mythos 5.5 code is already embedded in its official site. Anthropic is also heading toward a rumored mega IPO in mid-November, so its stage is already hot.
The more grounded explanation, in my view, is simpler: these three giants now ship on near-weekly cycles. Gemini 4 Carbon took the throne on October 28, and in a race like that, the only available response is to show your next card as fast as possible, even if the card appears in the form of a leak.
My yardstick stays the same
My measure has always been simple: a model is judged by independent testing and by whether I can actually use it, not by how dramatic its leak is. Today, only one thing is certain: a three-way fight at the top is underway, and two of the three players have not officially shown their cards.
If one of these models actually ships on November 3 or 4 with a model card and public access, then we can talk about numbers worth holding on to. Until then, GPT-6.2 Astra and Claude 5.5 share the same status: fascinating, widely reported, and unproven.
Sources: KuCoin/AIBase (November 2, 2026), ChainCatcher (November 2, 2026).
