{
  "cveId": "CVE-2026-19566",
  "url": "https://patchblox.com/security/cve/CVE-2026-19566",
  "summary": "CVE-2026-19566 is fixed in libnet-cidr-set-perl on 1 platform by DEBIAN-CVE-2026-19566 (version 0.23-1), released August 17, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libnet-cidr-set-perl: Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 pref...",
  "description": "Net::CIDR::Set versions before 0.23 for Perl allow memory exhaustion and malformed set ranges via unbounded IPv6 prefix lengths.  The _encode method accepts any prefix length matching \u0060(0|[1-9][0-9]*)\u0060 and passes it to _width2bits(), which builds the mask as \u0060\u00271\u0027 x ($width \u002B 8)\u0060, one character per bit. The _inc() method then unpacks the packed mask into a Perl array of one scalar per byte, so the prefix length alone sets the allocation size: \u0060::/100000000\u0060 builds a 100 MB string and a 12.5 million element array. The value being tested is parsed, not just the configured ranges: contains() builds a set from its argument, and _guess_coder() tries the IPv4 coder and then the IPv6 coder, so an IPv4-only set expands an oversized IPv6 prefix length before the mixed address width check rejects it.  Any caller that passes untrusted input to contains() or add() can exhaust process memory. A prefix length above 128 is also stored as a range that does not match the requested block: 2001:db8::/129 stringifies back unchanged, contains() of its own base address returns false, and removing it from a set drops the base address while the set still prints as covering it.",
  "published": "2026-08-12T09:17:29Z",
  "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": 0.0063,
  "epssPercentile": 0.50458,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libnet-cidr-set-perl",
      "release": "Debian 14",
      "fixedVersion": "0.23-1",
      "fix": "DEBIAN-CVE-2026-19566",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-19566",
      "released": "2026-08-17T22:58:38Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}