lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files

{
  "id": "977cef22c92b7745b2f2a30cb7ba45f8bc7d92b790e6b0ef17e7d17c9ffafce6",
  "url": "https://osv.dev/vulnerability/CVE-2026-41066",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files",
    "summary": "lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.0, using either of the two parsers in the default configuration (with resolve_entities=True) allows untrusted XML input to read local files. Setting the resolve_entities option explicitly to resolve_entities='internal' or resolve_entities=False disables the local file access. This vulnerability is fixed in 6.1.0.",
    "evidence": "osv:CVE-2026-41066",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-41066",
      "aliases": [
        "CVE-2026-41066",
        "GHSA-vfmq-68hx-4jfw",
        "PYSEC-2026-87"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/lxml/lxml",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "43722f4402afa48b7890a96ce012eb0b9b1af5be"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "6.1.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:lxml:lxml:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "6.1.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "lxml-6.0.4",
            "lxml-6.0.3",
            "lxml-6.0.2",
            "lxml-6.0.1",
            "lxml-6.0.0",
            "lxml-5.3.0",
            "lxml-5.2.1",
            "lxml-5.2.0",
            "lxml-5.1.1",
            "lxml-5.1.0-2",
            "lxml-5.1.0-1",
            "lxml-5.1.0",
            "lxml-5.0.0",
            "lxml-4.9.2",
            "lxml-5.0a0",
            "lxml-4.9.1",
            "lxml-4.9.0",
            "lxml-4.8.0",
            "lxml-4.7.1",
            "lxml-4.7.0",
            "lxml-4.7.0-pre",
            "lxml-4.6.3",
            "lxml-4.6.2",
            "lxml-4.6.1",
            "lxml-4.6.0",
            "lxml-4.5.2",
            "lxml-4.5.1",
            "lxml-4.5.0",
            "lxml-4.4.1",
            "lxml-4.4.0",
            "lxml-4.3.2",
            "lxml-4.3.1",
            "lxml-4.3.0",
            "lxml-4.2.2",
            "lxml-4.2.1",
            "lxml-4.2.0",
            "lxml-4.1.1",
            "lxml-4.1.0",
            "lxml-4.0.0",
            "lxml-3.8.0-py27fix",
            "lxml-3.8.0",
            "lxml-3.7.2",
            "lxml-3.7.1",
            "lxml-3.7.0",
            "lxml-3.6.1",
            "lxml-3.6.0",
            "lxml-3.5.0",
            "lxml-3.5.0b1",
            "lxml-3.4.1",
            "lxml-3.4.0",
            "lxml-3.4.0beta1",
            "lxml-3.3.3",
            "lxml-3.3.2",
            "lxml-3.3.1",
            "lxml-3.3.0",
            "lxml-3.3.0beta5",
            "lxml-3.3.0beta4",
            "lxml-3.3.0beta3",
            "lxml-3.3.0beta2",
            "lxml-3.3.0beta1",
            "lxml-3.2.3",
            "lxml-3.2.2",
            "lxml-3.2.1",
            "lxml-3.2.0",
            "lxml-3.1.1",
            "lxml-3.1.0",
            "lxml-3.1beta1",
            "lxml-3.0.1",
            "lxml-3.0",
            "lxml-3.0beta1",
            "lxml-3.0alpha2",
            "lxml-3.0alpha1",
            "lxml-2.3.1",
            "lxml-2.3",
            "lxml-2.3beta1",
            "lxml-2.3alpha2",
            "lxml-2.3alpha1",
            "lxml-2.2.2",
            "lxml-2.2.1",
            "lxml-2.2",
            "lxml-2.1",
            "lxml-2.1beta3",
            "lxml-2.1beta2",
            "lxml-2.1beta1",
            "lxml-2.1alpha1",
            "lxml-2.0.1",
            "lxml-2.0",
            "lxml-2.0beta2",
            "lxml-2.0beta1",
            "lxml-2.0alpha6",
            "lxml-2.0alpha5",
            "lxml-2.0alpha4",
            "lxml-2.0alpha3",
            "lxml-2.0alpha2",
            "lxml-2.0alpha1",
            "lxml-1.2",
            "lxml-1.1",
            "lxml-1.1beta",
            "lxml-1.1alpha",
            "lxml-1.0",
            "lxml-1.0.beta",
            "lxml-0.9",
            "lxml-0.7",
            "lxml-0.6",
            "lxml-0.5.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-41066.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.649610398Z",
      "provider": "osv",
      "references": [
        "https://bugs.launchpad.net/lxml/+bug/2146291",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41066.json",
        "https://github.com/lxml/lxml/security/advisories/GHSA-vfmq-68hx-4jfw",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-41066"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-611"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41066.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-41066",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493371,
  "published_at": "2026-04-24T16:45:19.617+00:00"
}