{
  "cveId": "CVE-2026-13577",
  "url": "https://patchblox.com/security/cve/CVE-2026-13577",
  "summary": "CVE-2026-13577 is fixed in 3 products on 1 platform, first by DEBIAN-CVE-2026-13577, released July 20, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "libdancer2-perl: Dancer2 versions before 2.2.0 for Perl generate insecure session ids when required CSPRNG modules are unavailable",
  "description": "Dancer2 versions before 2.2.0 for Perl generate insecure session ids when required CSPRNG modules are unavailable.  Dancer2::Core::Role::SessionFactory::generate_id silently falls back to a built-in rand-derived session id unless both Math::Random::ISAAC::XS and Crypt::URandom are available.  The fallback session id is generated from a SHA-1 hash of a call to the built-in rand function, the absolute path of the Dancer2::Core::Role::SessionFactory module, an internal counter, the process id, the module instance memory address, and a shuffled string of characters (using the List::Util::shuffle function, which also uses the built-in rand function).  These are all low-entropy and easily guessed sources.  The built-in rand() function is seeded with 32-bits and considered unsuitable for security applications.  Predictable session ids could allow an attacker to gain access to systems.",
  "published": "2026-07-20T08:16:28Z",
  "severity": "high",
  "cvss": 8.2,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
  "epss": 0.0057,
  "epssPercentile": 0.47425,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "dancer2",
      "release": "Fedora 43",
      "fixedVersion": "1.1.2-4.fc43",
      "fix": "FEDORA-2026-D0BEDEDB87",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-d0bededb87",
      "released": "2026-09-06T22:58:53Z"
    },
    {
      "platform": "linux",
      "product": "libdancer2-perl",
      "release": "Debian 14",
      "fixedVersion": "2.2.2-1",
      "fix": "DEBIAN-CVE-2026-13577",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-13577",
      "released": "2026-07-20T08:16:28Z"
    },
    {
      "platform": "linux",
      "product": "perl-Dancer2",
      "release": "Fedora 43",
      "fixedVersion": "1.1.2-4.fc43",
      "fix": "FEDORA-2026-D0BEDEDB87",
      "url": "https://patchblox.com/security/fix/linux/fedora-2026-d0bededb87",
      "released": "2026-09-06T22:58:53Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}