{"id":39836,"date":"2026-01-27T08:05:45","date_gmt":"2026-01-27T07:05:45","guid":{"rendered":"https:\/\/borncity.com\/win\/?p=39836"},"modified":"2026-01-27T08:06:02","modified_gmt":"2026-01-27T07:06:02","slug":"microsoft-office-0-day-vulnerability-cve-2026-21509-emergency-updates-available","status":"publish","type":"post","link":"https:\/\/borncity.com\/win\/2026\/01\/27\/microsoft-office-0-day-vulnerability-cve-2026-21509-emergency-updates-available\/","title":{"rendered":"Microsoft Office 0-day vulnerability CVE-2026-21509; Emergency updates available"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft\" src=\"https:\/\/borncity.com\/blog\/wp-content\/uploads\/2012\/07\/Office1.jpg\" width=\"55\" height=\"60\" align=\"left\" data-cmp-info=\"10\" \/>Microsoft Office 2016 to 2024 and Office 365 apps contain a zero-day vulnerability (CVE-2026-21509) that is being actively exploited in attacks. On January 26, 2026, Microsoft published initial information (also about mitigations) and emergency updates for Microsoft Office.<\/p>\n<p><!--more--><\/p>\n<p>Office 2021 upward has been patched server-side. For Office 2016 is an emergency update available, and Office 2019 got a C2R update for a new build. I've discussed the details in\u00a0<a href=\"https:\/\/borncity.com\/blog\/2026\/01\/27\/microsoft-office-0-day-schwachstelle-cve-2026-21509-notfall-updates-teilweise-verfuegbar\/\" target=\"_blank\" rel=\"noopener\">this article<\/a> [use the translation option in the side bar of my German blog to read the article in English or other languages].<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Microsoft Office 2016 to 2024 and Office 365 apps contain a zero-day vulnerability (CVE-2026-21509) that is being actively exploited in attacks. On January 26, 2026, Microsoft published initial information (also about mitigations) and emergency updates for Microsoft Office.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11,580,22],"tags":[125,69,195],"class_list":["post-39836","post","type-post","status-publish","format-standard","hentry","category-office","category-security","category-update","tag-office","tag-security","tag-update"],"_links":{"self":[{"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts\/39836","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/comments?post=39836"}],"version-history":[{"count":2,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts\/39836\/revisions"}],"predecessor-version":[{"id":39838,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts\/39836\/revisions\/39838"}],"wp:attachment":[{"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/media?parent=39836"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/categories?post=39836"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/tags?post=39836"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}