CVE-2026-45844: Software Security Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v3rr-h24h-xgqw",
  "modified" : "2026-10-15T03:35:55Z",
  "published" : "2026-05-27T12:31:23Z",
  "aliases" : [ "CVE-2026-45844" ],
  "details" : "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: arp_tables: fix IEEE1394 ARP payload parsing\n\nWeiming Shi says:\n\n\"arp_packet_match() unconditionally parses the ARP payload assuming two\nhardware addresses are present (source and target). However,\nIPv4-over-IEEE1394 ARP (RFC 2734) omits the target hardware address\nfield, and arp_hdr_len() already accounts for this by returning a\nshorter length for ARPHRD_IEEE1394 devices.\n\nAs a result, on IEEE1394 interfaces arp_packet_match() advances past a\nnonexistent target hardware address and reads the wrong bytes for both\nthe target device address comparison and the target IP address. This\ncauses arptables rules to match against garbage data, leading to\nincorrect filtering decisions: packets that should be accepted may be\ndropped and vice versa.\n\nThe ARP stack in net/ipv4/arp.c (arp_create and arp_process) already\nhandles this correctly by skipping the target hardware address for\nARPHRD_IEEE1394. Apply the same pattern to arp_packet_match().\"\n\nMangle the original patch to always return 0 (no match) in case user\nmatches on the target hardware address which is never present in\nIEEE1394.\n\nNote that this returns 0 (no match) for either normal and inverse match\nbecause matching in the target hardware address in ARPHRD_IEEE1394 has\nnever been supported by arptables. This is intentional, matching on the\ntarget hardware address should never evaluate true for ARPHRD_IEEE1394.\n\nMoreover, adjust arpt_mangle to drop the packet too as AI suggests:\n\nIn arpt_mangle, the logic assumes a standard ARP layout. Because\nIEEE1394 (FireWire) omits the target hardware address, the linear\npointer arithmetic miscalculates the offset for the target IP address.\nThis causes mangling operations to write to the wrong location, leading\nto packet corruption. To ensure safety, this patch drops packets\n(NF_DROP) when mangling is requested for these fields on IEEE1394\ndevices, as the current implementation cannot correctly map the FireWire\nARP payload.\n\nThis omits both mangling target hardware and IP address. Even if IP\naddress mangling should be possible in IEEE1394, this would require\nto adjust arpt_mangle offset calculation, which has never been\nsupported.\n\nBased on patch from Weiming Shi <bestswngs@gmail.com>.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-45844"
  }, {
    "type" : "WEB",
    "url" : "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/03ea11dbefaa55c502735ee551c89ef773fe753b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/0f23a1457695f1a61f64367e39f0f9cfa29947d1"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/1c55053f8ffdc060006df898fd3664e3d1bfac7b"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/1e285362ef7096eb12733370d59e033f4a1d294a"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/1e8e3f449b1e73b73a843257635b9c50f0cc0f0a"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/84e8536c981338d0d8cc6e712cf71a936a93e13f"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ac698d81fd6619c7504cee913f1cab5285fba1b7"
  }, {
    "type" : "WEB",
    "url" : "https://git.kernel.org/stable/c/ad9973df8e0eeb123d9ec4d18828e05b7d44ff4b"
  } ],
  "database_specific" : {
    "cwe_ids" : [ ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-05-27T11:16:23Z"
  }
}