{"id":251906,"date":"2026-05-21T18:06:00","date_gmt":"2026-05-21T22:06:00","guid":{"rendered":"https:\/\/news-you-need.com\/index.php\/2026\/05\/21\/microsoft-patches-two-zero-day-flaws-in-defender\/"},"modified":"2026-05-21T18:35:21","modified_gmt":"2026-05-21T22:35:21","slug":"microsoft-patches-two-zero-day-flaws-in-defender","status":"publish","type":"post","link":"https:\/\/news-you-need.com\/index.php\/2026\/05\/21\/microsoft-patches-two-zero-day-flaws-in-defender\/","title":{"rendered":"Microsoft patches two zero-day flaws in Defender"},"content":{"rendered":"<p><a href=\"https:\/\/www.csoonline.com\/article\/4175970\/microsoft-patches-two-zero-day-flaws-in-defender.html\">Microsoft patches two zero-day flaws in Defender<\/a><\/p>\n<p><a href=\"https:\/\/www.csoonline.com\/article\/4175970\/microsoft-patches-two-zero-day-flaws-in-defender.html\">https:\/\/www.csoonline.com\/article\/4175970\/microsoft-patches-two-zero-day-flaws-in-defender.html<\/a><\/p>\n<p>Publish Date: <a href=\"publish_date]\">2026-05-21 18:06:00<\/a><\/p>\n<p>Source Domain: <a href=\"www.csoonline.com\">www.csoonline.com<\/a><\/p>\n<p>On Wednesday, the United States Cybersecurity and Infrastructure Security Agency (CISA), added the two vulnerabilities, tracked as CVE-2026-41091 and CVE-2026-45498, to its Known Exploited Vulnerabilities (KEV) catalog, signaling that exploitation was detected in the wild.<\/p>\n<p>Security experts report that the two flaws are behind the RedSun and UnDefend exploits published last month on GitHub by a disgruntled researcher who calls themselves Nightmare Eclipse. While plausible, Microsoft has not mentioned those exploit names in its advisories for these two vulnerabilities.<\/p>\n<p>The privilege escalation flaw, CVE-2026-41091, is located in mpengine.dll, the Microsoft Malware Protection Engine (MPE) component that handles file scanning, malware detection, and cleaning in several Microsoft anti-malware products: Microsoft Defender, Microsoft System Center Endpoint Protection, Microsoft System Center 2012 R2 Endpoint Protection, Microsoft System Center 2012 Endpoint Protection, and Microsoft Security Essentials.<\/p>\n<p>The vulnerability is described as an improper link resolution before file access issue. In other words, it\u2019s related to a link- or shortcut-following routine that has unintended consequences. The flaw is rated with a CVSS score of 7.8, meaning high severity.<\/p>\n<p><a href=\"https:\/\/www.csoonline.com\/article\/4175970\/microsoft-patches-two-zero-day-flaws-in-defender.html\">Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Microsoft patches two zero-day flaws in Defender https:\/\/www.csoonline.com\/article\/4175970\/microsoft-patches-two-zero-day-flaws-in-defender.html Publish Date: 2026-05-21 18:06:00 Source Domain: www.csoonline.com&#8230;<\/p>\n","protected":false},"author":1,"featured_media":251907,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"fifu_image_url":"https:\/\/www.csoonline.com\/wp-content\/uploads\/2026\/05\/4175970-0-11801700-1779401164-bernard-hermant-rfpSOlH1JlQ-unsplash.jpg?quality=50&strip=all&w=1024","fifu_image_alt":"","footnotes":""},"categories":[15],"tags":[24,31,32,27],"class_list":["post-251906","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-cybersecurity","tag-cybersecurity","tag-exploit","tag-malware","tag-vulnerability"],"_links":{"self":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/251906"}],"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=251906"}],"version-history":[{"count":1,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/251906\/revisions"}],"predecessor-version":[{"id":251908,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/posts\/251906\/revisions\/251908"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media\/251907"}],"wp:attachment":[{"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/media?parent=251906"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/categories?post=251906"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news-you-need.com\/index.php\/wp-json\/wp\/v2\/tags?post=251906"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}