{
  "threat_severity" : "Moderate",
  "public_date" : "2026-03-25T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: bpf: Fix stack-out-of-bounds write in devmap",
    "id" : "2451202",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2451202"
  },
  "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-787",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nbpf: Fix stack-out-of-bounds write in devmap\nget_upper_ifindexes() iterates over all upper devices and writes their\nindices into an array without checking bounds.\nAlso the callers assume that the max number of upper devices is\nMAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack,\nbut that assumption is not correct and the number of upper devices could\nbe larger than MAX_NEST_DEV (e.g., many macvlans), causing a\nstack-out-of-bounds write.\nAdd a max parameter to get_upper_ifindexes() to avoid the issue.\nWhen there are too many upper devices, return -EOVERFLOW and abort the\nredirect.\nTo reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with\nan XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS.\nThen send a packet to the device to trigger the XDP redirect path.", "A flaw was found in the Linux kernel. The `get_upper_ifindexes()` function, which collects network device indices, fails to check array boundaries when writing these indices. This allows a local attacker to create a large number of virtual network interfaces (macvlans), causing a stack-out-of-bounds write. The consequence is a denial of service (DoS), as the system aborts network packet redirection, affecting network availability." ],
  "statement" : "This flaw affects systems using XDP (eXpress Data Path) with BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS on devices with many upper interfaces (>8 macvlans). The stack buffer overflow occurs because MAX_NEST_DEV assumption doesn't hold for all configurations. Requires ability to create many macvlan interfaces and attach XDP programs.",
  "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" : "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" : "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-2026-23359\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-23359\nhttps://lore.kernel.org/linux-cve-announce/2026032538-CVE-2026-23359-35fd@gregkh/T" ],
  "name" : "CVE-2026-23359",
  "csaw" : false
}