{"id":78504,"date":"2026-05-15T09:46:20","date_gmt":"2026-05-15T06:16:20","guid":{"rendered":"https:\/\/afaghhosting.net\/blog\/cve-2026-43490-ksmbd-validate-inherited-ace-sid-length\/"},"modified":"2026-05-15T09:46:20","modified_gmt":"2026-05-15T06:16:20","slug":"cve-2026-43490-ksmbd-validate-inherited-ace-sid-length","status":"publish","type":"post","link":"https:\/\/afaghhosting.net\/blog\/cve-2026-43490-ksmbd-validate-inherited-ace-sid-length\/","title":{"rendered":"CVE-2026-43490 &#8211; ksmbd: validate inherited ACE SID length"},"content":{"rendered":"<p>CVE ID :CVE-2026-43490<\/p>\n<p>  Published : May 15, 2026, 6:16 a.m. | 1\u00a0hour, 41\u00a0minutes ago<\/p>\n<p>  Description :In the Linux kernel, the following vulnerability has been resolved:<\/p>\n<p>ksmbd: validate inherited ACE SID length<\/p>\n<p>smb_inherit_dacl() walks the parent directory DACL loaded from the<br \/>\nsecurity descriptor xattr. It verifies that each ACE contains the fixed<br \/>\nSID header before using it, but does not verify that the variable-length<br \/>\nSID described by sid.num_subauth is fully contained in the ACE.<\/p>\n<p>A malformed inheritable ACE can advertise more subauthorities than are<br \/>\npresent in the ACE. compare_sids() may then read past the ACE.<br \/>\nsmb_set_ace() also clamps the copied destination SID, but used the<br \/>\nunchecked source SID count to compute the inherited ACE size. That could<br \/>\nadvance the temporary inherited ACE buffer pointer and nt_size accounting<br \/>\npast the allocated buffer.<\/p>\n<p>Fix this by validating the parent ACE SID count and SID length before<br \/>\nusing the SID during inheritance. Compute the inherited ACE size from the<br \/>\ncopied SID so the size matches the bounded destination SID. Reject the<br \/>\ninherited DACL if size accumulation would overflow smb_acl.size or the<br \/>\nsecurity descriptor allocation size.<\/p>\n<p>  Severity: 0.0 | NA<\/p>\n<p>  Visit the link for more details, such as CVSS details, affected products, timeline, and more&#8230;\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"<p>CVE ID :CVE-2026-43490 Published : May 15, 2026, 6:16 a.m. | 1\u00a0hour, 41\u00a0minutes ago Description :In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate inherited ACE SID length smb_inherit_dacl() walks the parent directory DACL loaded from the security descriptor xattr. It verifies that each ACE contains the fixed SID header before using &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"class_list":["post-78504","post","type-post","status-publish","format-standard","hentry","category-vulnerability"],"_links":{"self":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/78504","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/comments?post=78504"}],"version-history":[{"count":0,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/posts\/78504\/revisions"}],"wp:attachment":[{"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/media?parent=78504"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/categories?post=78504"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/afaghhosting.net\/blog\/wp-json\/wp\/v2\/tags?post=78504"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}