{
   "document": {
      "category": "csaf_security_advisory",
      "csaf_version": "2.0",
      "distribution": {
         "tlp": {
            "label": "WHITE",
            "url": "https://www.first.org/tlp/"
         }
      },
      "lang": "en",
      "notes": [
         {
            "category": "description",
            "text": "Dancer2 versions through 2.1.0 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.",
            "title": "Vulnerability Description"
         }
      ],
      "publisher": {
         "category": "other",
         "contact_details": "gdt@cpan.org",
         "name": "giterlizzi",
         "namespace": "https://github.com/giterlizzi/"
      },
      "references": [
         {
            "category": "self",
            "summary": "CPANSA-Dancer2-2026-13577 JSON",
            "url": "https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-dancer2-2026-13577.json"
         },
         {
            "category": "external",
            "summary": "https://github.com/PerlDancer/Dancer2/blob/v2.1.0/lib/Dancer2/Core/Role/SessionFactory.pm#L142",
            "url": "https://github.com/PerlDancer/Dancer2/blob/v2.1.0/lib/Dancer2/Core/Role/SessionFactory.pm#L142"
         },
         {
            "category": "external",
            "summary": "https://www.cve.org/CVERecord?id=CVE-2026-5080",
            "url": "https://www.cve.org/CVERecord?id=CVE-2026-5080"
         },
         {
            "category": "external",
            "summary": "CVE-2026-13577 (NVD)",
            "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-13577"
         }
      ],
      "title": "Dancer2 vulnerability",
      "tracking": {
         "current_release_date": "2026-07-20T00:00:00",
         "generator": {
            "engine": {
               "name": "CSAF Perl Toolkit",
               "version": "0.26"
            }
         },
         "id": "CPANSA-Dancer2-2026-13577",
         "initial_release_date": "2026-07-20T00:00:00",
         "revision_history": [
            {
               "date": "2026-07-20T00:00:00",
               "number": "1",
               "summary": "First release"
            }
         ],
         "status": "final",
         "version": "1"
      }
   },
   "product_tree": {
      "branches": [
         {
            "branches": [
               {
                  "category": "product_version_range",
                  "name": "vers:cpan/>0",
                  "product": {
                     "name": "Dancer2 greater than 0",
                     "product_id": "CSAFPID-0001",
                     "product_identification_helper": {
                        "purl": "pkg:cpan/Dancer2"
                     }
                  }
               }
            ],
            "category": "product_name",
            "name": "Dancer2"
         }
      ]
   },
   "vulnerabilities": [
      {
         "cve": "CVE-2026-13577",
         "cwe": {
            "id": "CWE-338",
            "name": "Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)"
         },
         "notes": [
            {
               "category": "description",
               "text": "Dancer2 versions through 2.1.0 for Perl generate insecure session ids when required CSPRNG modules are unavailable.\n\nDancer2::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.\n\nThe 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).\n\nThese are all low-entropy and easily guessed sources.\n\nThe built-in rand() function is seeded with 32-bits and considered unsuitable for security applications.\n\nPredictable session ids could allow an attacker to gain access to systems.",
               "title": "Vulnerability Description"
            }
         ],
         "product_status": {
            "known_affected": [
               "CSAFPID-0001"
            ]
         },
         "scores": [
            {
               "cvss_v3": {
                  "baseScore": 8.2,
                  "baseSeverity": "HIGH",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H",
                  "version": "3.1"
               },
               "products": [
                  "CSAFPID-0001"
               ]
            }
         ]
      }
   ]
}