{"id":269336,"date":"2026-06-10T07:00:00","date_gmt":"2026-06-10T11:00:00","guid":{"rendered":"https:\/\/news-you-need.com\/index.php\/2026\/06\/10\/new-anthropic-fable-5-is-a-mythos-class-llm-available-to-all\/"},"modified":"2026-06-10T10:50:27","modified_gmt":"2026-06-10T14:50:27","slug":"new-anthropic-fable-5-is-a-mythos-class-llm-available-to-all","status":"publish","type":"post","link":"https:\/\/news-you-need.com\/index.php\/2026\/06\/10\/new-anthropic-fable-5-is-a-mythos-class-llm-available-to-all\/","title":{"rendered":"New Anthropic Fable 5 Is a “Mythos-Class” LLM Available to All"},"content":{"rendered":"

New Anthropic Fable 5 Is a “Mythos-Class” LLM Available to All<\/a><\/p>\n

https:\/\/www.infosecurity-magazine.com\/news\/fable-5-mythos-class-anthropic\/<\/a><\/p>\n

Publish Date: 2026-06-10 07:00:00<\/a><\/p>\n

Source Domain: www.infosecurity-magazine.com<\/a><\/p>\n

Just days after expanding its cybersecurity-focused frontier AI program, Project Glasswing, Anthropic released two new models, Claude Mythos 5 and Claude Fable 5.<\/p>\n

Mythos 5 has been presented by Anthropic as \u201can upgrade to Claude Mythos Preview\u201d and the AI company claimed in a June 9 announcement that it has \u201cthe strongest cybersecurity capabilities of any model in the world.\u201d<\/p>\n

This new upgrade will initially be deployed through Project Glasswing, in collaboration with the US government, but the company plans for a wider availability of the model in the future via \u201ca broader trusted access program.\u201d<\/p>\n

Meanwhile, Fable 5 has is said to be powered by the same underlying frontier AI model as Mythos 5 but with additional guardrails, especially in areas like cybersecurity where the company said it \u201ccould be misused to cause serious damage.\u201d<\/p>\n

One of these safeguards involves a system where queries made by Fable 5 on certain topics will receive a response from Claude Opus 4.8, Anthropic\u2019s next-in-line model that is available to everyone.<\/p>\n

\u201cTo release the model both safely and quickly, we\u2019ve tuned these safeguards conservatively \u2013 they\u2019ll sometimes catch harmless requests, though they trigger, on average, in less than 5% of sessions,\u201d cautioned the AI company, adding that is it working on new models where these safeguards will be fine-tuned to reduce false positives.<\/p>\n

Fable 5 and Mythos 5 are being offered at $10 per million input tokens and $50 per million output tokens, less than half the price of Claude Mythos Preview at $25 per million input tokens and $125 per million output tokens.<\/p>\n

Quickly following the Anthropic announcement, Microsoft said Fable 5 is now available in Microsoft Foundry and can be used to power agents in GitHub Copilot and Foundry Agent Service.<\/p>\n

Fable\u2019s Guardrails May Not Be Sufficient, Cyber Experts Warn<\/strong><\/h2>\n

The Anthropic announcement generated mixed feelings in the cybersecurity industry.<\/p>\n

Sachin Puri, CEO of Network…<\/p>\n

Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

New Anthropic Fable 5 Is a “Mythos-Class” LLM Available to All https:\/\/www.infosecurity-magazine.com\/news\/fable-5-mythos-class-anthropic\/ Publish Date: 2026-06-10…<\/p>\n","protected":false},"author":1,"featured_media":269338,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/assets.infosecurity-magazine.com\/webpage\/og\/505620e6-2263-469f-8de4-6706d4e58527.jpg","fifu_image_alt":"","footnotes":""},"categories":[15],"tags":[26,24,17],"class_list":["post-269336","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cybersecurity","tag-ai","tag-cybersecurity","tag-llm"],"_links":{"self":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/269336"}],"collection":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/comments?post=269336"}],"version-history":[{"count":1,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/269336\/revisions"}],"predecessor-version":[{"id":269339,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/269336\/revisions\/269339"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media\/269338"}],"wp:attachment":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media?parent=269336"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/categories?post=269336"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/tags?post=269336"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}