CVE-2026-13713

{
  "id": "CVE-2026-13713",
  "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
  "published": "2026-07-16T22:16:59.640",
  "lastModified": "2026-10-24T20:10:00.137",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack.\n\nIn the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser's value stack, so syck_hdlr_add_node reaches it again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it.\n\nAny caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service."
    },
    {
      "lang": "es",
      "value": "Las versiones de YAML::Syck anteriores a la 1.47 para Perl permiten un uso después de liberación y una doble liberación a través de un nodo ancla liberado mientras aún está en la pila de valores del analizador.\n\nEn la libsyck incluida, cuando un nombre de ancla es redefinido o eliminado, syck_hdlr_add_anchor y syck_hdlr_remove_anchor liberan el nodo almacenado bajo ese nombre con syck_free_node. Ese nodo aún puede estar activo en la pila de valores del analizador, por lo que syck_hdlr_add_node lo alcanza de nuevo y lo libera una segunda vez. En una compilación normal, el fragmento de nodo de 48 bytes es liberado dos veces y el intérprete aborta. Los anclas no necesitan banderas especiales, por lo que esto se alcanza en la ruta de carga (Load) predeterminada, y un documento de 7 bytes que redefine un ancla lo activa.\n\nCualquier llamador que ejecute Load o LoadFile en un documento no confiable que redefine un ancla a mitad del análisis bloquea el intérprete, una denegación de servicio."
    }
  ],
  "affected": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "affectedData": [
        {
          "vendor": "TODDR",
          "product": "YAML::Syck",
          "defaultStatus": "unaffected",
          "collectionURL": "https://cpan.org/modules",
          "packageName": "YAML-Syck",
          "programFiles": [
            "handler.c",
            "syck_.c",
            "syck.h"
          ],
          "programRoutines": [
            {
              "name": "syck_hdlr_add_anchor"
            },
            {
              "name": "syck_hdlr_remove_anchor"
            },
            {
              "name": "syck_hdlr_add_node"
            }
          ],
          "repo": "https://github.com/toddr/YAML-Syck",
          "versions": [
            {
              "version": "0",
              "lessThan": "1.47",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 6.2,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-17T13:17:36.382946Z",
          "id": "CVE-2026-13713",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-415"
        },
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes",
      "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e"
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2026/07/17/1",
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ]
}