{"id":"INC-anthropic-bhphxz3vr58g","kind":"incident","aliases":[],"related":[],"title":"Anthropic: Elevated errors for Claude Mythos 5.1 and Claude Fable 5.1","description":"The issue affecting Claude Mythos 5.1 and Claude Fable 5.1 has been resolved. Impact occurred from 05:40 PT / 12:40 UTC to 06:10 PT / 13:10 UTC.","summary":null,"severity":"high","cvss":null,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"Anthropic","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["ai","anthropic","incident","llm","ops","vendor"],"not_affected_if":[],"how_to_check":null,"fix":null,"status":"resolved","published_at":"2026-10-05T13:05:44+00:00","first_seen_at":"2026-10-23T19:12:22+00:00","triaged_at":"2026-10-23T20:20:06+00:00","updated_at":"2026-10-23T20:20:06+00:00","category":"vendor","confidence":null,"triage":null,"analyst_status":null,"analyst_note":null,"search":"'05':39C '06':46C '10':47C,50C '12':42C '13':49C '40':40C,43C '5.1':7A,11A,28C,32C 'affect':25C 'ai':17B 'anthrop':1A,18B 'anthropic':14A,16A 'bhphxz3vr58g':15A 'claud':5A,9A,26C,30C 'elev':2A 'error':3A 'fabl':10A,31C 'impact':36C 'inc':13A 'inc-anthropic-bhphxz3vr58g':12A 'incid':19B 'issu':24C 'llm':20B 'mytho':6A,27C 'occur':37C 'op':21B 'pt':41C,48C 'resolv':35C 'utc':44C,51C 'vendor':22B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-05T13:05:44+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"statuspage","external_id":"anthropic:bhphxz3vr58g","url":"https://stspg.io/wdqhxt8xt574","severity":"high","published_at":"2026-10-05T13:05:44+00:00","modified_at":"2026-10-05T13:21:37+00:00","first_seen_at":"2026-10-23T19:12:22+00:00","fetched_at":"2026-10-25T18:54:09+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}