CVE-2026-13713 affecting package perl-YAML 1.30-2

{
  "id": "2b55d0174c65c3b8fdb09ec8ea3043d856ae1f17e19124a666b875e3f47c9cd3",
  "url": "https://osv.dev/vulnerability/AZL-109520",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2026-13713 affecting package perl-YAML 1.30-2",
    "summary": "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. In 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. Any caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.",
    "evidence": "osv:AZL-109520",
    "products": [
      {
        "name": {
          "value": "perl-YAML",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "AZL-109520",
      "aliases": [
        "AZL-109520"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "1.30-2"
                }
              ]
            }
          ],
          "package": {
            "name": "perl-YAML",
            "purl": "pkg:rpm/azure-linux/perl-YAML",
            "ecosystem": "Azure Linux:3"
          },
          "database_specific": {
            "source": "https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-109520.json"
          }
        }
      ],
      "modified": "2026-10-27T05:36:16Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-13713"
      ],
      "references": [
        "https://nvd.nist.gov/vuln/detail/CVE-2026-13713"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-13713",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 460469,
  "published_at": "2026-07-16T22:16:59+00:00"
}