{
  "threat_severity" : "Moderate",
  "public_date" : "2026-04-22T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: netfs: Fix kernel BUG in netfs_limit_iter() for ITER_KVEC iterators",
    "id" : "2460733",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2460733"
  },
  "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-843",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nnetfs: Fix kernel BUG in netfs_limit_iter() for ITER_KVEC iterators\nWhen a process crashes and the kernel writes a core dump to a 9P\nfilesystem, __kernel_write() creates an ITER_KVEC iterator. This\niterator reaches netfs_limit_iter() via netfs_unbuffered_write(), which\nonly handles ITER_FOLIOQ, ITER_BVEC and ITER_XARRAY iterator types,\nhitting the BUG() for any other type.\nFix this by adding netfs_limit_kvec() following the same pattern as\nnetfs_limit_bvec(), since both kvec and bvec are simple segment arrays\nwith pointer and length fields. Dispatch it from netfs_limit_iter() when\nthe iterator type is ITER_KVEC.", "A flaw was found in the Linux kernel's netfs component. When a process crashes and the kernel attempts to write a core dump to a 9P filesystem, the `netfs_limit_iter()` function does not properly handle `ITER_KVEC` iterators. This oversight can lead to a kernel BUG, resulting in a system crash and a Denial of Service (DoS) for the affected system." ],
  "statement" : "Upstream corrected netfs iterator handling so core dumps to 9P-backed storage no longer hit a deliberate BUG() in `netfs_limit_iter()`. Red Hat treats this as a local availability issue tied to that uncommon configuration. Apply updated kernels when published. No discrete loadable-module mitigation applies to netfs itself.",
  "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" : "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-2026-31438\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31438\nhttps://lore.kernel.org/linux-cve-announce/2026042243-CVE-2026-31438-66c2@gregkh/T" ],
  "name" : "CVE-2026-31438",
  "csaw" : false
}