{
  "threat_severity" : "Moderate",
  "public_date" : "2026-07-19T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: NFSv4/flexfiles: reject zero filehandle version count",
    "id" : "2502240",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2502240"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.0",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
    "status" : "verified"
  },
  "cwe" : "CWE-476",
  "details" : [ "In the Linux kernel, the following vulnerability has been resolved:\nNFSv4/flexfiles: reject zero filehandle version count\nff_layout_alloc_lseg() decodes the filehandle-version array count\nfrom the flexfiles layout body. The value is used as the count for\nkzalloc_objs(), and the current code only rejects NULL.\nA zero count yields ZERO_SIZE_PTR, which can be stored in\ndss_info->fh_versions even though later flexfiles paths assume that at\nleast one filehandle version exists.\nReject fh_count == 0 before the allocation, matching the existing zero\nversion_count validation in the flexfiles GETDEVICEINFO parser.\nA QEMU/KASAN run with a malformed flexfiles layout hit:\nKASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]\nRIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750\nff_layout_encode_layoutreturn+0x683/0x970\nnfs4_xdr_enc_layoutreturn+0x278/0x3a0\nKernel panic - not syncing: Fatal exception\nThe patched kernel rejects the malformed layout without KASAN/oops/panic,\nand a valid fh_count=1 regression still opens, reads, and unmounts cleanly.", "A flaw was found in the Linux kernel's NFSv4 (Network File System version 4) flexfiles component. This vulnerability occurs when the ff_layout_alloc_lseg() function processes a malformed flexfiles layout that specifies a zero filehandle version count. An attacker could exploit this by providing a specially crafted flexfiles layout, leading to a null-pointer dereference and ultimately causing a kernel panic, resulting in a Denial of Service (DoS) for the system." ],
  "affected_release" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "release_date" : "2026-09-01T00:00:00Z",
    "advisory" : "RHSA-2026:61887",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10.2",
    "package" : "kernel-0:6.12.0-211.50.1.el10_2"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63013",
    "cpe" : "cpe:/a:redhat:enterprise_linux:8::nfv",
    "package" : "kernel-rt-0:4.18.0-553.159.1.rt7.500.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "release_date" : "2026-09-03T00:00:00Z",
    "advisory" : "RHSA-2026:63014",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8",
    "package" : "kernel-0:4.18.0-553.159.1.el8_10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-09-04T00:00:00Z",
    "advisory" : "RHSA-2026:63129",
    "cpe" : "cpe:/a:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.44.1.el9_8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "release_date" : "2026-09-04T00:00:00Z",
    "advisory" : "RHSA-2026:63129",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9",
    "package" : "kernel-0:5.14.0-687.44.1.el9_8"
  } ],
  "package_state" : [ {
    "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" : "Affected",
    "package_name" : "kernel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "kernel-rt",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-53392\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53392\nhttps://lore.kernel.org/linux-cve-announce/2026071956-CVE-2026-53392-540c@gregkh/T" ],
  "name" : "CVE-2026-53392",
  "csaw" : false
}