{
   "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": "YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.  The heap overflow occurs when class names exceed the initial 512-byte allocation.  The base64 decoder could read past the buffer end on trailing newlines.  strtok mutated n->type_id in place, corrupting shared node data.  A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.",
            "title": "Vulnerability Description"
         }
      ],
      "publisher": {
         "category": "other",
         "contact_details": "gdt@cpan.org",
         "name": "giterlizzi",
         "namespace": "https://github.com/giterlizzi/"
      },
      "references": [
         {
            "category": "self",
            "summary": "CPANSA-YAML-Syck-2026-4177 JSON",
            "url": "https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-yaml-syck-2026-4177.json"
         },
         {
            "category": "external",
            "summary": "https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch",
            "url": "https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch"
         },
         {
            "category": "external",
            "summary": "https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21",
            "url": "https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21"
         },
         {
            "category": "external",
            "summary": "http://www.openwall.com/lists/oss-security/2026/03/16/6",
            "url": "http://www.openwall.com/lists/oss-security/2026/03/16/6"
         },
         {
            "category": "external",
            "summary": "CVE-2026-4177 (NVD)",
            "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4177"
         }
      ],
      "title": "YAML-Syck vulnerability",
      "tracking": {
         "current_release_date": "2026-03-16T00:00:00",
         "generator": {
            "engine": {
               "name": "CSAF Perl Toolkit",
               "version": "0.26"
            }
         },
         "id": "CPANSA-YAML-Syck-2026-4177",
         "initial_release_date": "2026-03-16T00:00:00",
         "revision_history": [
            {
               "date": "2026-03-16T00:00:00",
               "number": "1",
               "summary": "First release"
            }
         ],
         "status": "final",
         "version": "1"
      }
   },
   "product_tree": {
      "branches": [
         {
            "branches": [
               {
                  "category": "product_version_range",
                  "name": "vers:cpan/>0",
                  "product": {
                     "name": "YAML-Syck greater than 0",
                     "product_id": "CSAFPID-0001",
                     "product_identification_helper": {
                        "purl": "pkg:cpan/YAML-Syck"
                     }
                  }
               }
            ],
            "category": "product_name",
            "name": "YAML-Syck"
         }
      ]
   },
   "vulnerabilities": [
      {
         "cve": "CVE-2026-4177",
         "cwe": {
            "id": "CWE-122",
            "name": "Heap-based Buffer Overflow"
         },
         "notes": [
            {
               "category": "description",
               "text": "YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.\n\nThe heap overflow occurs when class names exceed the initial 512-byte allocation.\n\nThe base64 decoder could read past the buffer end on trailing newlines.\n\nstrtok mutated n->type_id in place, corrupting shared node data.\n\nA memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.",
               "title": "Vulnerability Description"
            }
         ],
         "product_status": {
            "known_affected": [
               "CSAFPID-0001"
            ]
         },
         "scores": [
            {
               "cvss_v3": {
                  "baseScore": 9.1,
                  "baseSeverity": "CRITICAL",
                  "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
                  "version": "3.1"
               },
               "products": [
                  "CSAFPID-0001"
               ]
            }
         ]
      }
   ]
}