{"id":48727,"date":"2026-04-22T10:29:54","date_gmt":"2026-04-22T10:29:54","guid":{"rendered":"http:\/\/localhost\/?p=48727"},"modified":"2026-04-22T10:29:54","modified_gmt":"2026-04-22T10:29:54","slug":"missing-large-page-handling-in-pmappkruupdaterange","status":"publish","type":"post","link":"https:\/\/zero.redgem.net\/?p=48727","title":{"rendered":"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386"},"content":{"rendered":"<p>{&#8220;lastseen&#8221;:&#8221;&#8221;,&#8221;description&#8221;:&#8221;In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries.  The subroutine which handled this failed to take into account the presence of 1GB largepage mappings created using the shm_create_largepage(3) interface.  In particular, it would always treat a page directory page entry as pointing to another page table page.\\n\\nThe bug can be abused by an unprivileged user to cause pmap_pkru_update_range() to treat userspace memory as a page table page, and thus overwrite memory to which the application would otherwise not have access.&#8221;,&#8221;published&#8221;:&#8221;2026-04-22T02:33:24.846Z&#8221;,&#8221;modified&#8221;:&#8221;2026-04-22T14:32:53.989Z&#8221;,&#8221;type&#8221;:&#8221;cve&#8221;,&#8221;title&#8221;:&#8221;Missing large page handling in pmap_pkru_update_range()&#8221;,&#8221;source&#8221;:&#8221;freebsd&#8221;,&#8221;references&#8221;:&#8221;https:\/\/security.freebsd.org\/advisories\/FreeBSD-SA-26:11.amd64.asc&#8221;,&#8221;id&#8221;:&#8221;CVE-2026-6386&#8243;,&#8221;bulletinFamily&#8221;:&#8221;&#8221;,&#8221;cwe&#8221;:[&#8220;CWE-269&#8243;,&#8221;CWE-732&#8243;],&#8221;cvelist&#8221;:null,&#8221;sourceData&#8221;:&#8221;FreeBSD FreeBSD 15.0-RELEASE\\nFreeBSD FreeBSD 14.4-RELEASE\\nFreeBSD FreeBSD 14.3-RELEASE\\nFreeBSD FreeBSD 13.5-RELEASE&#8221;,&#8221;sourceHref&#8221;:&#8221;&#8221;,&#8221;cvss&#8221;:{&#8220;score&#8221;:6.2,&#8221;severity&#8221;:&#8221;MEDIUM&#8221;,&#8221;vector&#8221;:&#8221;CVSS:3.1\/AV:L\/AC:L\/PR:N\/UI:N\/S:U\/C:H\/I:N\/A:N&#8221;,&#8221;version&#8221;:&#8221;3.1&#8243;},&#8221;cvss2&#8243;:{},&#8221;cvss3&#8243;:{&#8220;version&#8221;:&#8221;&#8221;,&#8221;vectorString&#8221;:&#8221;&#8221;,&#8221;baseScore&#8221;:0,&#8221;baseSeverity&#8221;:&#8221;&#8221;,&#8221;attackVector&#8221;:&#8221;&#8221;,&#8221;attackComplexity&#8221;:&#8221;&#8221;,&#8221;privilegesRequired&#8221;:&#8221;&#8221;,&#8221;userInteraction&#8221;:&#8221;&#8221;,&#8221;scope&#8221;:&#8221;&#8221;,&#8221;confidentialityImpact&#8221;:&#8221;&#8221;,&#8221;integrityImpact&#8221;:&#8221;&#8221;,&#8221;availabilityImpact&#8221;:&#8221;&#8221;,&#8221;cvssV3&#8243;:{&#8220;version&#8221;:&#8221;&#8221;,&#8221;vectorString&#8221;:&#8221;&#8221;,&#8221;baseScore&#8221;:0,&#8221;baseSeverity&#8221;:&#8221;&#8221;,&#8221;attackVector&#8221;:&#8221;&#8221;,&#8221;attackComplexity&#8221;:&#8221;&#8221;,&#8221;privilegesRequired&#8221;:&#8221;&#8221;,&#8221;userInteraction&#8221;:&#8221;&#8221;,&#8221;scope&#8221;:&#8221;&#8221;,&#8221;confidentialityImpact&#8221;:&#8221;&#8221;,&#8221;integrityImpact&#8221;:&#8221;&#8221;,&#8221;availabilityImpact&#8221;:&#8221;&#8221;}},&#8221;href&#8221;:&#8221;&#8221;,&#8221;category_name&#8221;:&#8221;CVE&#8221;,&#8221;post_link&#8221;:&#8221;&#8221;,&#8221;product&#8221;:&#8221;FreeBSD&#8221;,&#8221;version&#8221;:&#8221;15.0-RELEASE&#8221;,&#8221;vendor&#8221;:&#8221;FreeBSD&#8221;,&#8221;ai_description&#8221;:&#8221;&#8221;,&#8221;ai_severity&#8221;:&#8221;&#8221;,&#8221;ai_vendor&#8221;:&#8221;&#8221;,&#8221;ai_product&#8221;:&#8221;&#8221;,&#8221;ai_version&#8221;:&#8221;&#8221;,&#8221;ai_score&#8221;:0}<\/p>\n","protected":false},"excerpt":{"rendered":"<p>{&#8220;lastseen&#8221;:&#8221;&#8221;,&#8221;description&#8221;:&#8221;In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries. The subroutine which handled&#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":[6,8,102,12,21,13,7,11,5],"class_list":["post-48727","post","type-post","status-publish","format-standard","hentry","category-category_cve","tag-cve","tag-cvss","tag-cvss-62","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>Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386 - 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=48727\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386 - zero redgem\" \/>\n<meta property=\"og:description\" content=\"{&#8220;lastseen&#8221;:&#8221;&#8221;,&#8221;description&#8221;:&#8221;In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries. The subroutine which handled...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/zero.redgem.net\/?p=48727\" \/>\n<meta property=\"og:site_name\" content=\"zero redgem\" \/>\n<meta property=\"article:published_time\" content=\"2026-04-22T10:29:54+00:00\" \/>\n<meta name=\"author\" content=\"invoker\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"invoker\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727\"},\"author\":{\"name\":\"invoker\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#\\\/schema\\\/person\\\/fbfeae8dfad117ac08a7621bee1a1dca\"},\"headline\":\"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386\",\"datePublished\":\"2026-04-22T10:29:54+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727\"},\"wordCount\":243,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#organization\"},\"keywords\":[\"CVE\",\"CVSS\",\"CVSS-6.2\",\"exploit\",\"MEDIUM\",\"news\",\"Security\",\"tapic\",\"Vulnerability\"],\"articleSection\":[\"category_cve\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/zero.redgem.net\\\/?p=48727#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727\",\"url\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727\",\"name\":\"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386 - zero redgem\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#website\"},\"datePublished\":\"2026-04-22T10:29:54+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/zero.redgem.net\\\/?p=48727\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/?p=48727#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/zero.redgem.net\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#website\",\"url\":\"https:\\\/\\\/zero.redgem.net\\\/\",\"name\":\"zero redgem\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/zero.redgem.net\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#organization\",\"name\":\"zero redgem\",\"url\":\"https:\\\/\\\/zero.redgem.net\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"\",\"contentUrl\":\"\",\"width\":191,\"height\":188,\"caption\":\"zero redgem\"},\"image\":{\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#\\\/schema\\\/logo\\\/image\\\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/zero.redgem.net\\\/#\\\/schema\\\/person\\\/fbfeae8dfad117ac08a7621bee1a1dca\",\"name\":\"invoker\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f17c01d7338e6932bcde121cf83569393df3374625d25afd62677cfb528f2e3e?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f17c01d7338e6932bcde121cf83569393df3374625d25afd62677cfb528f2e3e?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/f17c01d7338e6932bcde121cf83569393df3374625d25afd62677cfb528f2e3e?s=96&d=mm&r=g\",\"caption\":\"invoker\"},\"sameAs\":[\"https:\\\/\\\/zero.redgem.net\"],\"url\":\"https:\\\/\\\/zero.redgem.net\\\/?author=1\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386 - zero redgem","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/zero.redgem.net\/?p=48727","og_locale":"en_US","og_type":"article","og_title":"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386 - zero redgem","og_description":"{&#8220;lastseen&#8221;:&#8221;&#8221;,&#8221;description&#8221;:&#8221;In order to apply a particular protection key to an address range, the kernel must update the corresponding page table entries. The subroutine which handled...","og_url":"https:\/\/zero.redgem.net\/?p=48727","og_site_name":"zero redgem","article_published_time":"2026-04-22T10:29:54+00:00","author":"invoker","twitter_card":"summary_large_image","twitter_misc":{"Written by":"invoker","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/zero.redgem.net\/?p=48727#article","isPartOf":{"@id":"https:\/\/zero.redgem.net\/?p=48727"},"author":{"name":"invoker","@id":"https:\/\/zero.redgem.net\/#\/schema\/person\/fbfeae8dfad117ac08a7621bee1a1dca"},"headline":"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386","datePublished":"2026-04-22T10:29:54+00:00","mainEntityOfPage":{"@id":"https:\/\/zero.redgem.net\/?p=48727"},"wordCount":243,"commentCount":0,"publisher":{"@id":"https:\/\/zero.redgem.net\/#organization"},"keywords":["CVE","CVSS","CVSS-6.2","exploit","MEDIUM","news","Security","tapic","Vulnerability"],"articleSection":["category_cve"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/zero.redgem.net\/?p=48727#respond"]}]},{"@type":"WebPage","@id":"https:\/\/zero.redgem.net\/?p=48727","url":"https:\/\/zero.redgem.net\/?p=48727","name":"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386 - zero redgem","isPartOf":{"@id":"https:\/\/zero.redgem.net\/#website"},"datePublished":"2026-04-22T10:29:54+00:00","breadcrumb":{"@id":"https:\/\/zero.redgem.net\/?p=48727#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/zero.redgem.net\/?p=48727"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/zero.redgem.net\/?p=48727#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/zero.redgem.net\/"},{"@type":"ListItem","position":2,"name":"Missing large page handling in pmap_pkru_update_range()_CVE-2026-6386"}]},{"@type":"WebSite","@id":"https:\/\/zero.redgem.net\/#website","url":"https:\/\/zero.redgem.net\/","name":"zero redgem","description":"","publisher":{"@id":"https:\/\/zero.redgem.net\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/zero.redgem.net\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/zero.redgem.net\/#organization","name":"zero redgem","url":"https:\/\/zero.redgem.net\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/zero.redgem.net\/#\/schema\/logo\/image\/","url":"","contentUrl":"","width":191,"height":188,"caption":"zero redgem"},"image":{"@id":"https:\/\/zero.redgem.net\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/zero.redgem.net\/#\/schema\/person\/fbfeae8dfad117ac08a7621bee1a1dca","name":"invoker","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/f17c01d7338e6932bcde121cf83569393df3374625d25afd62677cfb528f2e3e?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/f17c01d7338e6932bcde121cf83569393df3374625d25afd62677cfb528f2e3e?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/f17c01d7338e6932bcde121cf83569393df3374625d25afd62677cfb528f2e3e?s=96&d=mm&r=g","caption":"invoker"},"sameAs":["https:\/\/zero.redgem.net"],"url":"https:\/\/zero.redgem.net\/?author=1"}]}},"_links":{"self":[{"href":"https:\/\/zero.redgem.net\/index.php?rest_route=\/wp\/v2\/posts\/48727","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zero.redgem.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zero.redgem.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zero.redgem.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zero.redgem.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=48727"}],"version-history":[{"count":0,"href":"https:\/\/zero.redgem.net\/index.php?rest_route=\/wp\/v2\/posts\/48727\/revisions"}],"wp:attachment":[{"href":"https:\/\/zero.redgem.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=48727"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zero.redgem.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=48727"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zero.redgem.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=48727"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}