{"id":40075,"date":"2026-04-12T00:01:45","date_gmt":"2026-04-11T22:01:45","guid":{"rendered":"https:\/\/borncity.com\/win\/?p=40075"},"modified":"2026-04-11T23:46:34","modified_gmt":"2026-04-11T21:46:34","slug":"adobe-reader-emergency-patch-for-0-day-vulnerability-cve-2026-34621","status":"publish","type":"post","link":"https:\/\/borncity.com\/win\/2026\/04\/12\/adobe-reader-emergency-patch-for-0-day-vulnerability-cve-2026-34621\/","title":{"rendered":"Adobe Reader: Emergency patch for 0-day vulnerability CVE-2026-34621"},"content":{"rendered":"

\"Sicherheit[German<\/a>]A few hours ago, I reported on a zero-day vulnerability in Adobe Reader. Simply opening a PDF file can be enough to take control of the system. Adobe has now confirmed the vulnerability (CVE-2026-34621) and released a security update to patch it. This should be installed within 72 hours.<\/p>\n

<\/p>\n

Adobe Reader 0-day is exploited in the wild<\/h2>\n

\"\"There is a 0-day vulnerability in Adobe Reader that has been exploited since December 2025. Security researcher Haifei Li discovered an exploit in his sandbox-based exploit detection platform EXPMON<\/a> that takes advantage of a previously unknown vulnerability. Haifei Li wrote that he had discovered a sophisticated zero-day fingerprinting attack targeting Adobe Reader users.<\/p>\n

The exploit takes advantage of a zero-day vulnerability in Adobe Reader that allows privileged Acrobat APIs to be executed. The exploit calls util.readFileIntoStream()<\/em> via the API, enabling it to read arbitrary files (to which the Reader process running in a sandbox has access) on the local system.<\/p>\n

In this way, malware can collect a wide range of information from the local system and steal local file data. I reported on the issue in the German blog post 0-day-Schwachstelle in Adobe Reader seit Dez. 2025 ausgenutzt<\/a>. Haifei Li published details in a blog post<\/a> on April 7, 2026.<\/p>\n

Adobe confirms vulnerability CVE-2026-34621<\/h2>\n

I just came across the information, that Adobe has confirmed the discovery of the zero-day vulnerability. And Adobe has released emergency patches to fix vulnerability\u00a0CVE-2026-34621. I've compiled the details within my German blog post\u00a0Adobe Reader Notfallpatch f\u00fcr 0-Day-Schwachstelle CVE-2026-34621<\/a> [use the build-in translator of my blog to read the article in your language].<\/p>\n","protected":false},"excerpt":{"rendered":"

[German]A few hours ago, I reported on a zero-day vulnerability in Adobe Reader. Simply opening a PDF file can be enough to take control of the system. Adobe has now confirmed the vulnerability (CVE-2026-34621) and released a security update to … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[580,1547,22],"tags":[286,69,1544,195],"class_list":["post-40075","post","type-post","status-publish","format-standard","hentry","category-security","category-software","category-update","tag-adobe-reader","tag-security","tag-software","tag-update"],"_links":{"self":[{"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts\/40075","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=40075"}],"version-history":[{"count":1,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts\/40075\/revisions"}],"predecessor-version":[{"id":40076,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/posts\/40075\/revisions\/40076"}],"wp:attachment":[{"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/media?parent=40075"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/categories?post=40075"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/borncity.com\/win\/wp-json\/wp\/v2\/tags?post=40075"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}