Security advisory

{
  "id": "4d85fee8efd1aea98c06669fb1cd107f124bb1b88104fefefa17e31c1b1dfdfa",
  "url": "https://osv.dev/vulnerability/CVE-2021-4235",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-4235",
    "summary": "Due to unbounded alias chasing, a maliciously crafted YAML file can cause the system to consume significant system resources. If parsing user input, this may be used as a denial of service vector.",
    "evidence": "osv:CVE-2021-4235",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-4235",
      "aliases": [
        "CVE-2021-4235",
        "GHSA-r88r-gmrh-7j83",
        "GO-2021-0061"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/go-yaml/yaml",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "bb4e33bf68bf89cad44d386192cbed201f35b241"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:yaml_project:yaml:*:*:*:*:*:go:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.2.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "bb4e33bf68bf89cad44d386192cbed201f35b241"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.2.2",
            "v2.2.1",
            "v2.2.0",
            "v2.1.1",
            "v2.1.0",
            "v2.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-4235.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:04.268986529Z",
      "provider": "osv",
      "references": [
        "https://lists.debian.org/debian-lts-announce/2023/07/msg00001.html",
        "https://pkg.go.dev/vuln/GO-2021-0061",
        "https://github.com/go-yaml/yaml/commit/bb4e33bf68bf89cad44d386192cbed201f35b241",
        "https://github.com/go-yaml/yaml/pull/375"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-4235",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 384838,
  "published_at": "2022-12-27T22:15:11.96+00:00"
}