{
  "cveId": "CVE-2026-56123",
  "url": "https://patchblox.com/security/cve/CVE-2026-56123",
  "summary": "CVE-2026-56123 is fixed in 3 products on 1 platform, first by socat 1.8.1.1-1ubuntu0.1, released June 25, 2026. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "socat: socat versions 1.8.0.0 through 1.8.1.1 contain a heap-based buffer overflow vulnerability that allows a malicious SOC...",
  "description": "socat versions 1.8.0.0 through 1.8.1.1 contain a heap-based buffer overflow vulnerability that allows a malicious SOCKS5 proxy server to overwrite adjacent heap memory by exploiting a sign-extension flaw in the DOMAINNAME reply parser. During connection setup, the domain name length byte is read through a signed char field causing a negative bytes_to_read value that is implicitly converted to size_t, resulting in an unbounded heap write into the 262-byte reply buffer with attacker-controlled size and content.",
  "published": "2026-06-25T10:17:00Z",
  "severity": "critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00314,
  "epssPercentile": 0.24531,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "socat",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.8.0.3-1\u002Bdeb13u1",
      "fix": "DEBIAN-CVE-2026-56123",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-56123",
      "released": "2026-07-03T14:54:39Z"
    },
    {
      "platform": "linux",
      "product": "socat",
      "release": "Debian 14",
      "fixedVersion": "1.8.1.3-1",
      "fix": "DEBIAN-CVE-2026-56123",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-56123",
      "released": "2026-07-03T14:54:39Z"
    },
    {
      "platform": "linux",
      "product": "socat",
      "release": "Fedora 43",
      "fixedVersion": "1.8.1.3-1.fc43",
      "fix": "FEDORA-2026-232FFC1325",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-232ffc1325",
      "released": "2026-10-07T08:18:40Z"
    },
    {
      "platform": "linux",
      "product": "socat",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "1.8.0.0-4ubuntu0.1",
      "fix": "socat 1.8.0.0-4ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-socat-1.8.0.0-4ubuntu0.1",
      "released": "2026-07-07T15:29:03Z"
    },
    {
      "platform": "linux",
      "product": "socat",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "1.8.1.1-1ubuntu0.1",
      "fix": "socat 1.8.1.1-1ubuntu0.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-socat-1.8.1.1-1ubuntu0.1",
      "released": "2026-06-25T10:17:00Z"
    },
    {
      "platform": "linux",
      "product": "socat-debuginfo",
      "release": "Fedora 43",
      "fixedVersion": "1.8.1.3-1.fc43",
      "fix": "FEDORA-2026-232FFC1325",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-232ffc1325",
      "released": "2026-10-07T08:18:40Z"
    },
    {
      "platform": "linux",
      "product": "socat-debugsource",
      "release": "Fedora 43",
      "fixedVersion": "1.8.1.3-1.fc43",
      "fix": "FEDORA-2026-232FFC1325",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-232ffc1325",
      "released": "2026-10-07T08:18:40Z"
    }
  ],
  "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"
  }
}