{"id":138098,"date":"2026-05-14T17:41:07","date_gmt":"2026-05-14T17:41:07","guid":{"rendered":"https:\/\/christiancorner.us\/index.php\/2026\/05\/14\/anthropics-mythos-is-evolving-faster-than-expected-ai-security-agency-reports\/"},"modified":"2026-05-14T17:44:02","modified_gmt":"2026-05-14T17:44:02","slug":"anthropics-mythos-is-evolving-faster-than-expected-ai-security-agency-reports","status":"publish","type":"post","link":"https:\/\/christiancorner.us\/index.php\/2026\/05\/14\/anthropics-mythos-is-evolving-faster-than-expected-ai-security-agency-reports\/","title":{"rendered":"Anthropic&#8217;s mythos is evolving faster than expected, AI security agency reports"},"content":{"rendered":"<p>\n<\/p>\n<div>\n<figure class=\"c-shortcodeImage u-clearfix c-shortcodeImage-large\">\n<div class=\"c-shortcodeImage_imageContainer\">\n<div class=\"c-shortcodeImage_image\"><picture class=\"c-cmsImage c-cmsImage_loaded\" style=\"aspect-ratio:1280\/853.3333333333333;\"><source media=\"(max-width: 767px)\" srcset=\"https:\/\/www.zdnet.com\/a\/img\/resize\/d64920e422185a1385fce07da9aeede6d16a57bd\/2026\/05\/14\/e9d8706a-b03f-4a26-9e3b-8f944d134bcf\/aiburst-gettyimages-2189115060.jpg?auto=webp&amp;width=768\" alt=\"aiburst-gettyimages-2189115060\"><source media=\"(max-width: 1023px)\" srcset=\"https:\/\/www.zdnet.com\/a\/img\/resize\/761d27bc2ba40c8faf84c453e288d39239f28111\/2026\/05\/14\/e9d8706a-b03f-4a26-9e3b-8f944d134bcf\/aiburst-gettyimages-2189115060.jpg?auto=webp&amp;width=1024\" alt=\"aiburst-gettyimages-2189115060\"><source media=\"(max-width: 1440px)\" srcset=\"https:\/\/www.zdnet.com\/a\/img\/resize\/9c8b9c1cdec36ca326f559aee24ec2e70d1b1582\/2026\/05\/14\/e9d8706a-b03f-4a26-9e3b-8f944d134bcf\/aiburst-gettyimages-2189115060.jpg?auto=webp&amp;width=1280\" alt=\"aiburst-gettyimages-2189115060\"><\/source><\/source><\/source><\/picture><\/div>\n<p> <!----><\/div><figcaption> <span class=\"c-shortcodeImage_credit g-outer-spacing-top-xsmall u-block\">Eugene Mymrin\/Moment via Getty Images<\/span><\/figcaption><\/figure>\n<p><em>Follow ZDNET: <\/em><span class=\"c-commerceLink\"><a rel=\"noopener nofollow sponsored\" target=\"_blank\" href=\"https:\/\/cc.zdnet.com\/v1\/otc\/00hQi47eqnEWQ6T9d4QLBUc?element=BODY&amp;element_label=Add+us+as+a+preferred+Google+source&amp;module=LINK&amp;object_type=text-link&amp;object_uuid=5e5d2e64-4b30-43e6-8555-26eac7e449f3&amp;position=1&amp;template=article&amp;track_code=__COM_CLICK_ID__&amp;url=https%3A%2F%2Fwww.google.com%2Fpreferences%2Fsource%3Fq%3Dzdnet.com&amp;view_instance_uuid=379e95d2-6b56-476b-a90b-043a8dd63bd3\"><span>Add us as a favorite source<\/span><!----><\/a><\/span><em>  On Google.<\/em><\/p>\n<hr\/>\n<h3>ZDNET Highlights<\/h3>\n<ul>\n<li>The latest version of Cloud Mythos has already been upgraded.<\/li>\n<li>External researchers found that it achieved several firsts in testing. <\/li>\n<li>AI capabilities may be improving faster than anticipated. <\/li>\n<\/ul>\n<hr\/>\n<p>Anthropic&#8217;s Cloud Mythos, which the company says is too powerful for general release, appears to have already gained new capabilities. <\/p>\n<p>one in <a rel=\"noopener nofollow\" target=\"_blank\" href=\"https:\/\/www.aisi.gov.uk\/blog\/how-fast-is-autonomous-ai-cyber-capability-advancing\" class=\"c-regularLink\">blog<\/a> Posting on Wednesday, the UK AI Security Institute (AISI) reported that it had tested a new version of Mythos that outperformed both its previous results and OpenAI&#8217;s GPT-5.5 \u2013 just a month after Mythos&#8217; initial release. <\/p>\n<p><strong>Also: Apple, Google and Microsoft join forces with Anthropic&#8217;s Project Glasswing to protect the world&#8217;s most critical software<\/strong><\/p>\n<p>The blog authors wrote, &#8220;The new Mythos Preview checkpoint completed both of our cyber ranges, solving &#8216;The Last Ones&#8217; in 6 out of 10 attempts and the previously unsolved &#8216;Cooling Tower&#8217; in 3 out of 10 attempts.&#8221; \u201cThis was the first time a model completed the second of our two cyber ranges.\u201d <\/p>\n<p>When Anthropic first announced Mythos Preview and Project Glasswing \u2013 the cybersecurity testing alliance it formed with rival tech companies and AI labs, to which it gave limited access to Mythos \u2013 last month, the UK AISI <a rel=\"noopener nofollow\" target=\"_blank\" href=\"https:\/\/www.aisi.gov.uk\/blog\/our-evaluation-of-claude-mythos-previews-cyber-capabilities\" class=\"c-regularLink\">rated it<\/a>Finding that the model &#8220;represents a step forward over previous frontier models in a scenario where cyber performance was already rapidly improving.&#8221; <\/p>\n<p>That third-party perspective helped balance claims that the hype around the Mythos was either purely marketing or, at the other extreme, signaled a catastrophic shift in AI capabilities. The truth about what the model can do is likely to lie somewhere in the middle. <\/p>\n<p><strong>Also: How to learn cloud code for free with Anthropic&#8217;s AI courses \u2013 one only took me 20 minutes<\/strong><\/p>\n<p>AISI&#8217;s updated testing also exemplifies that capability improvements are not limited to individual model releases, but can also occur within versions of a single model. <\/p>\n<h2>rapidly growing cyber threat <\/h2>\n<p>AISI noted that AI models are rapidly advancing in their ability to handle cyber tasks with serious implications for cybersecurity, especially given the ability of Mythos to detect software vulnerabilities. <\/p>\n<p>\u201cIn February 2026, we internally estimated that the duration of cyber tasks that could be completed by AI models would double every 4.7 months by the end of 2024 \u2013 already an acceleration from our November 2025 8-month estimate,\u201d the blog authors wrote. &#8220;Since then, AISI reported on two new models, Cloud Mythos Preview and (OpenAI&#8217;s) GPT-5.5, both of which significantly exceed doubling rate trends.&#8221; <\/p>\n<p><strong>Also: Third major Linux kernel flaw found in two weeks \u2013 thanks to AI<\/strong><\/p>\n<p>The authors said it is unclear whether this trend will persist or whether these findings indicate a permanent increase. The Mythos and GPT-5.5 models may be notable breaks from the overall pattern of development. <\/p>\n<p>Nevertheless, AISI clarified that there were many unknowns that could not be determined in its testing. The tests limited the tasks to 2.5 million tokens, allowing researchers to better compare performance results over time. \u201cThis naturally demonstrates what marginal models can do,\u201d he wrote. <\/p>\n<p>The blog continued, &#8220;Mythos Preview and GPT-5.5 have large upper bound error bars due to our narrow cyber suite&#8217;s near 100% success rate on the longest tasks, even with the 2.5M token limit.&#8221; &#8220;Our experiments are not long enough to determine how rapidly the model&#8217;s reliability will deteriorate over high task periods. This puts some of the newest models at the measurement limits of our narrow test suite.&#8221;<\/p>\n<p><strong>Also: I put GPT-5.5 through a 10-round test: it scored 93\/100, losing points only due to excitement<\/strong><\/p>\n<p>While this makes it harder to measure the model&#8217;s failure point, it also means that the model&#8217;s success rate on these tasks would be much higher than without the token limit \u2013 so high, in fact, that &#8220;it becomes impossible to calculate the time horizon.&#8221; Models with greater token access and complex agent infrastructure will be more efficient. <\/p>\n<p>The blog states, &#8220;The 2.5M token limit is relatively low \u2013 in our Cyber \u200b\u200bRange experiment we use up to 100M tokens and find that beyond that budget there is still potential for performance improvement, especially for recent models, which disproportionately benefit from the higher token limit.&#8221; <\/p>\n<\/div>\n<p><script type=\"text\/javascript\">\n      (function() {\n        window.zdconsent = window.zdconsent || {run:(),cmd:(),useractioncomplete:(),analytics:(),functional:(),social:()};\n        window.zdconsent.cmd = window.zdconsent.cmd || ();\n        window.zdconsent.cmd.push(function() {\n          !function(f,b,e,v,n,t,s)\n          {if(f.fbq)return;n=f.fbq=function(){n.callMethod?\n          n.callMethod.apply(n,arguments):n.queue.push(arguments)};\n          if(!f._fbq)f._fbq=n;n.push=n;n.loaded=!0;n.version='2.0';\n          n.queue=();t=b.createElement(e);t.async=!0;\n          t.src=v;s=b.getElementsByTagName(e)(0);\n          s.parentNode.insertBefore(t,s)}(window, document,'script',\n          'https:\/\/connect.facebook.net\/en_US\/fbevents.js');\n          fbq('set', 'autoConfig', false, '789754228632403');\n          fbq('init', '789754228632403');\n        });\n      })();\n    <\/script><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Eugene Mymrin\/Moment via Getty Images Follow ZDNET: Add us as a favorite source On Google. ZDNET Highlights The latest version of Cloud Mythos has already been upgraded. External researchers found that it achieved several firsts in testing. AI capabilities may be improving faster than anticipated. Anthropic&#8217;s Cloud Mythos, which the company says is too powerful<\/p>\n","protected":false},"author":1,"featured_media":138104,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[3561,4401,21865,565,564,19042,1739,543],"class_list":{"0":"post-138098","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-devotionals","8":"tag-agency","9":"tag-anthropics","10":"tag-evolving","11":"tag-expected","12":"tag-faster","13":"tag-mythos","14":"tag-reports","15":"tag-security"},"_links":{"self":[{"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/posts\/138098","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/comments?post=138098"}],"version-history":[{"count":1,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/posts\/138098\/revisions"}],"predecessor-version":[{"id":138105,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/posts\/138098\/revisions\/138105"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/media\/138104"}],"wp:attachment":[{"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/media?parent=138098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/categories?post=138098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/christiancorner.us\/index.php\/wp-json\/wp\/v2\/tags?post=138098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}