{"id":65960,"date":"2026-06-25T17:42:46","date_gmt":"2026-06-25T17:42:46","guid":{"rendered":"https:\/\/zero.redgem.net\/?p=65960"},"modified":"2026-06-25T17:42:46","modified_gmt":"2026-06-25T17:42:46","slug":"hmac-blake2-final-discards-message-when-key-length-exceeds-block-size","status":"publish","type":"post","link":"https:\/\/zero.redgem.net\/?p=65960","title":{"rendered":"HMAC-BLAKE2 final discards message when key length exceeds block size_CVE-2026-8720"},"content":{"rendered":"<p>{&#8220;lastseen&#8221;:&#8221;&#8221;,&#8221;description&#8221;:&#8221;wc_Blake2bHmacFinal and wc_Blake2sHmacFinal discard the message when the key length exceeds the block size, producing a MAC that is independent of the input. When the supplied key is longer than the BLAKE2 block size the key-hashing branch reinitialized the running hash state, discarding the accumulated message data, so the resulting MAC depended only on the key and not on the message being authenticated. 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When the&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[6,8,97,12,21,13,7,11,5],"class_list":["post-65960","post","type-post","status-publish","format-standard","hentry","category-category_cve","tag-cve","tag-cvss","tag-cvss-59","tag-exploit","tag-medium","tag-news","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>HMAC-BLAKE2 final discards message when key length exceeds block size_CVE-2026-8720 - zero redgem<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/zero.redgem.net\/?p=65960\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"HMAC-BLAKE2 final discards message when key length exceeds block size_CVE-2026-8720 - zero redgem\" \/>\n<meta property=\"og:description\" content=\"{&#8220;lastseen&#8221;:&#8221;&#8221;,&#8221;description&#8221;:&#8221;wc_Blake2bHmacFinal and wc_Blake2sHmacFinal discard the message when the key length exceeds the block size, producing a MAC that is independent of the input. 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