Yesterday in AI: 27 March 2026 — Leaks, IPOs, and a Million Paying Coders

Anthropic accidentally revealed its next-gen Mythos model and weighed an October IPO, while Cursor crossed one million paying developers and ByteDance open-sourced its Deer-Flow 2.0 super-agent framework.

By OMC Editorial on 2026-03-28

Anthropic Accidentally Unveils Claude Mythos The biggest AI story of the week arrived without a press release. Anthropic inadvertently left roughly 3,000 CMS assets publicly accessible, exposing draft documentation for an unreleased model codenamed Claude Mythos. According to the leaked materials, Mythos will sit above the Opus tier in a new "Capybara" product tier, with Anthropic's own internal testing describing it as "dramatically" better than Claude Opus 4.6 on programming and reasoning tasks. The company confirmed it is testing the model but disputed some details in the leaked files. Separately, Fortune reported that Anthropic had already detected and banned accounts belonging to a Chinese state-sponsored group that used Claude Code to compromise roughly 30 organizations. Cybersecurity stocks including Palo Alto Networks −6% and CrowdStrike −5% fell sharply on the news. Sources: Fortunehttps://fortune.com/2026/03/26/anthropic-says-testing-mythos-powerful-new-ai-model-after-data-leak-reveals-its-existence-step-change-in-capabilities/, SiliconANGLEhttps://siliconangle.com/2026/03/27/anthropic-launch-new-claude-mythos-model-advanced-reasoning-features/, Fortune cybersecurityhttps://fortune.com/2026/03/27/anthropic-leaked-ai-mythos-cybersecurity-risk/ --- Anthropic Weighs IPO as Early as October Bloomberg reported on Friday that Anthropic has opened early discussions with Wall Street banks about a potential IPO as soon as October 2026. The company — recently valued north of 0 billion — would be racing rival OpenAI to the public markets. No timeline is final, and the talks remain exploratory. The news capped a week in which Anthropic also adjusted Claude usage limits to throttle throughput during peak hours 05:00–11:00 PT / 13:00–19:00 GMT, a sign that capacity constraints are shaping product decisions ahead of any listing. Source: Bloomberghttps://www.bloomberg.com/news/articles/2026-03-27/claude-ai-maker-anthropic-said-to-weigh-ipo-as-soon-as-october ---