{
  "threat_severity" : "Moderate",
  "public_date" : "2026-04-27T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: igb: remove napi_synchronize() in igb_down()",
    "id" : "2463267",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2463267"
  },
  "cvss3" : {
    "cvss3_base_score" : "4.7",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
    "status" : "draft"
  },
  "cwe" : "CWE-833",
  "details" : [ "A flaw was found in the Linux kernel's igb network driver. When an AF_XDP zero-copy application terminates abruptly, the network driver's NAPI polling mechanism can become stuck. This prevents the igb_down() function from completing, leading to the TX queue becoming permanently stalled. This can result in a Denial of Service (DoS) condition, making the network interface unresponsive." ],
  "statement" : "igb can hang in igb_down when an AF_XDP zero copy application terminates abruptly and the XSK buffer pool is destroyed while NAPI polling keeps running. In this state the zero copy RX poll path can keep returning a full budget which prevents napi_complete_done from clearing NAPI_STATE_SCHED. igb_down then calls napi_synchronize and waits indefinitely for NAPI_STATE_SCHED to clear which never happens. This blocks the down path, triggers the TX watchdog, and can leave the TX queue permanently stalled which is a denial of service for the affected network device. The issue is not network reachable and requires local control of the host to set up and exercise AF_XDP zero copy.",
  "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-2026-31691\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31691\nhttps://lore.kernel.org/linux-cve-announce/2026042757-CVE-2026-31691-5c48@gregkh/T" ],
  "name" : "CVE-2026-31691",
  "mitigation" : {
    "value" : "To mitigate this issue, prevent module igb from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.",
    "lang" : "en:us"
  },
  "csaw" : false
}