{
  "public_date" : "2026-04-24T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: ksmbd: require 3 sub-authorities before reading sub_auth[2]",
    "id" : "2461574",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2461574"
  },
  "cwe" : "CWE-1285",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nksmbd: require 3 sub-authorities before reading sub_auth[2]\nparse_dacl() compares each ACE SID against sid_unix_NFS_mode and on\nmatch reads sid.sub_auth[2] as the file mode.  If sid_unix_NFS_mode is\nthe prefix S-1-5-88-3 with num_subauth = 2 then compare_sids() compares\nonly min(num_subauth, 2) sub-authorities so a client SID with\nnum_subauth = 2 and sub_auth = {88, 3} will match.\nIf num_subauth = 2 and the ACE is placed at the very end of the security\ndescriptor, sub_auth[2] will be  4 bytes past end_of_acl.  The\nout-of-band bytes will then be masked to the low 9 bits and applied as\nthe file's POSIX mode, probably not something that is good to have\nhappen.\nFix this up by forcing the SID to actually carry a third sub-authority\nbefore reading it at all.", "A flaw was found in the ksmbd component of the Linux kernel. A remote attacker could exploit this vulnerability by sending a specially crafted Access Control Entry (ACE) that causes an out-of-bounds read when parsing security identifiers. This out-of-bounds read can lead to the application of arbitrary, unintended data as a file's POSIX mode, potentially resulting in incorrect file permissions and unauthorized access to files." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Not affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-31611\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31611\nhttps://lore.kernel.org/linux-cve-announce/2026042422-CVE-2026-31611-6396@gregkh/T" ],
  "name" : "CVE-2026-31611",
  "csaw" : false
}