{
  "threat_severity" : "Low",
  "public_date" : "2026-04-24T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: xfrm: clear trailing padding in build_polexpire()",
    "id" : "2461482",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2461482"
  },
  "cvss3" : {
    "cvss3_base_score" : "5.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-908",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nxfrm: clear trailing padding in build_polexpire()\nbuild_expire() clears the trailing padding bytes of struct\nxfrm_user_expire after setting the hard field via memset_after(),\nbut the analogous function build_polexpire() does not do this for\nstruct xfrm_user_polexpire.\nThe padding bytes after the __u8 hard field are left\nuninitialized from the heap allocation, and are then sent to\nuserspace via netlink multicast to XFRMNLGRP_EXPIRE listeners,\nleaking kernel heap memory contents.\nAdd the missing memset_after() call, matching build_expire().", "A flaw was found in the Linux kernel's xfrm subsystem. This vulnerability arises because the `build_polexpire()` function does not clear trailing padding bytes within the `xfrm_user_polexpire` structure. Consequently, these uninitialized padding bytes, which contain kernel heap memory contents, are sent to userspace via netlink multicast. A local attacker could exploit this to disclose potentially sensitive information from kernel memory." ],
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Out of support scope",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-31664\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31664\nhttps://lore.kernel.org/linux-cve-announce/2026042405-CVE-2026-31664-d315@gregkh/T" ],
  "name" : "CVE-2026-31664",
  "csaw" : false
}