{
  "threat_severity" : "Moderate",
  "public_date" : "2026-07-19T00:00:00Z",
  "bugzilla" : {
    "description" : "kernel: NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr",
    "id" : "2502260",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2502260"
  },
  "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/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr\nnfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a\nnetaddr4 from a GETDEVICEINFO multipath-DS body, then immediately\ncalls strrchr(buf, '.') to locate the port separator. Both decodes\nuse xdr_stream_decode_string_dup(), and the current code checks only\n\"nlen < 0\" / \"rlen < 0\" before dereferencing the returned string.\nWhen the on-wire opaque has length zero, xdr_stream_decode_opaque_inline()\nreturns 0 and xdr_stream_decode_string_dup() falls through to its\n\"*str = NULL; return ret\" tail, leaving buf NULL with a return value\nof 0. The \"< 0\" check does not catch this, and the next line is\nstrrchr(NULL, '.'), a kernel NULL pointer dereference reachable from\nany pNFS-flexfile client mounted against a malicious or compromised\nmetadata server.\nReject the zero-length cases explicitly so the decoder fails with\n-EBADMSG (treated as a malformed GETDEVICEINFO body) instead of\npanicking the client.", "A flaw was found in the Linux kernel's NFSv4/pNFS implementation. The `nfs4_decode_mp_ds_addr` function, responsible for decoding network address information, does not properly handle zero-length `r_addr` opaque data. A malicious or compromised metadata server can exploit this by providing a zero-length `r_addr`, leading to a NULL pointer dereference and causing the client system to panic, resulting in a Denial of Service (DoS)." ],
  "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"
  }, {
    "product_name" : "Red Hat Hardened Images",
    "fix_state" : "Not affected",
    "package_name" : "erlang27",
    "cpe" : "cpe:/a:redhat:hummingbird:1",
    "impact" : "important"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-53391\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-53391\nhttps://lore.kernel.org/linux-cve-announce/2026071956-CVE-2026-53391-d4df@gregkh/T" ],
  "name" : "CVE-2026-53391",
  "csaw" : false
}