{
  "cveId": "CVE-2026-64194",
  "url": "https://patchblox.com/security/cve/CVE-2026-64194",
  "summary": "CVE-2026-64194 is fixed in 4 products on 1 platform, first by DEBIAN-CVE-2026-64194, released July 24, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libnet-dns-perl: Net::DNS versions through 1.55 for Perl allow Denial of Service via deep DNS compression pointer chains",
  "description": "Net::DNS versions through 1.55 for Perl allow Denial of Service via deep DNS compression pointer chains.  Net::DNS::DomainName::decode follows RFC 1035 compression pointers by recursing into itself with no depth limit. It is possible to construct a name which saturates the call stack (at least with larger TCP responses), leading to a potential Denial of Service.  The guard \u0060$link \u003C $offset\u0060 prevents forward and circular chains, but still allows arbitrarily long backward chains. The per-offset cache (\u0060$cache\u0060) is populated at the start of each call and short-circuits only re-traverses of the same offset - the initial descent through a fresh chain still recurses at full depth.  A crafted packet can chain two-byte compression pointers so that each one points two bytes earlier than the previous, producing a chain length of \u0060offset / 2\u0060. For the 14-bit pointer field (max offset 16383) this gives up to ~8191 recursive frames. For a TCP DNS message the limit is the 16-bit length field (~32767 frames). Perl\u0027s default C stack handles only a few thousand frames; beyond that the process receives SIGSEGV or similar, which is a denial-of-service for any application parsing untrusted DNS data.  The vulnerability is triggered by \u0060Net::DNS::Packet-\u003Enew(\\$wire)\u0060 i.e. any point where the library decodes a DNS message from the network.",
  "published": "2026-07-20T19:17:30Z",
  "severity": "high",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.0068,
  "epssPercentile": 0.52638,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libnet-dns-perl",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "1.36-1\u002Bdeb12u1",
      "fix": "DEBIAN-CVE-2026-64194",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64194",
      "released": "2026-07-24T13:34:41Z"
    },
    {
      "platform": "linux",
      "product": "libnet-dns-perl",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.56-0\u002Bdeb13u1",
      "fix": "DEBIAN-CVE-2026-64194",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64194",
      "released": "2026-07-24T13:34:41Z"
    },
    {
      "platform": "linux",
      "product": "libnet-dns-perl",
      "release": "Debian 14",
      "fixedVersion": "1.56-1",
      "fix": "DEBIAN-CVE-2026-64194",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-64194",
      "released": "2026-07-24T13:34:41Z"
    },
    {
      "platform": "linux",
      "product": "perl-Net-DNS",
      "release": "amzn 2023",
      "fixedVersion": "1.56-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-2046",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2046",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perl-Net-DNS",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "1.570.0-bp160.1.1",
      "fix": "OPENSUSE-SU-2026:21859-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21859-1",
      "released": "2026-09-15T13:20:42Z"
    },
    {
      "platform": "linux",
      "product": "perl-Net-DNS",
      "release": "sles 15.6",
      "fixedVersion": "1.14-150000.3.3.1",
      "fix": "SUSE-SU-2026:3456-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-3456-1",
      "released": "2026-08-03T11:50:38Z"
    },
    {
      "platform": "linux",
      "product": "perl-Net-DNS",
      "release": "sles 15.7",
      "fixedVersion": "1.14-150000.3.3.1",
      "fix": "SUSE-SU-2026:3456-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-3456-1",
      "released": "2026-08-03T11:50:38Z"
    },
    {
      "platform": "linux",
      "product": "perl-Net-DNS-Nameserver",
      "release": "amzn 2023",
      "fixedVersion": "1.56-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-2046",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2046",
      "released": "2026-08-03T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "perl-Net-DNS-tests",
      "release": "amzn 2023",
      "fixedVersion": "1.56-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-2046",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-2046",
      "released": "2026-08-03T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}