Security advisory

{
  "id": "361744c1eaa3e7de2ec08cee1574adc9ca1a47a96ae792ab8c248938bccd1c24",
  "url": "https://osv.dev/vulnerability/CVE-2021-42771",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-42771",
    "summary": "Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution.",
    "evidence": "osv:CVE-2021-42771",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-42771",
      "aliases": [
        "CVE-2021-42771",
        "GHSA-h4m5-qpfp-3mpv",
        "PYSEC-2021-421"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/python-babel/babel",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "a99fa2474c808b51ebdabea18db871e389751559"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:pocoo:babel:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.9.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.9.0",
            "v2.8.0",
            "v2.7.0",
            "v2.6.0",
            "v2.5.1",
            "v2.5.2",
            "v2.5.0",
            "v2.4.0",
            "dev-2a51c9b95d06",
            "2.0",
            "1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-42771.json"
          }
        }
      ],
      "modified": "2026-10-20T10:55:02.263494009Z",
      "provider": "osv",
      "references": [
        "https://lists.debian.org/debian-lts-announce/2021/10/msg00018.html",
        "https://lists.debian.org/debian-lts/2021/10/msg00040.html",
        "https://www.debian.org/security/2021/dsa-5018",
        "https://github.com/python-babel/babel/pull/782",
        "https://www.tenable.com/security/research/tra-2021-14"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*"
            ],
            "vendor_product": "debian:debian_linux",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "10.0"
                  },
                  {
                    "last_affected": "10.0"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-42771",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 386756,
  "published_at": "2021-10-20T21:15:07.93+00:00"
}