sqlparse: TokenList.__init__ materializes O(subtree) value per group, causing CPU DoS before depth/token caps trigger

{
  "id": "e9cb0076b2142127c329fd6cc5962c4777481725057134a8897798195b9265e3",
  "url": "https://osv.dev/vulnerability/CVE-2026-54284",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "sqlparse: TokenList.__init__ materializes O(subtree) value per group, causing CPU DoS before depth/token caps trigger",
    "summary": "sqlparse is a non-validating SQL parser module for Python. Prior to 0.6.0, TokenList construction and string conversion in sqlparse/sql.py repeatedly flatten nested token subtrees constructed by group_parenthesis and group_case, causing quadratic CPU consumption through sqlparse.parse(), sqlparse.format(), and sqlparse.split() before depth and token limits terminate processing. This issue is fixed in version 0.6.0.",
    "evidence": "osv:CVE-2026-54284",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-54284",
      "aliases": [
        "CVE-2026-54284",
        "GHSA-pwgv-4x5q-6m9f",
        "PYSEC-2026-3699"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/andialbrecht/sqlparse",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2f40da99b50d81135aecf96f6b08fcfa338a96de"
                },
                {
                  "fixed": "939b129e24c0ad5d51368b1aa72fffcaca76f06f"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.6.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "939b129e24c0ad5d51368b1aa72fffcaca76f06f"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.5.5",
            "0.5.4",
            "0.5.3",
            "0.5.2",
            "0.5.1",
            "0.5.0",
            "0.4.4",
            "0.4.3",
            "0.4.2",
            "0.4.1",
            "0.4.0",
            "0.3.1",
            "0.3.0",
            "0.2.4",
            "0.2.3",
            "0.2.2",
            "0.2.1",
            "0.2.0",
            "0.1.18",
            "0.1.17",
            "0.1.16",
            "0.1.15",
            "0.1.14",
            "0.1.13",
            "0.1.12",
            "0.1.11",
            "0.1.10",
            "0.1.9",
            "0.1.8",
            "0.1.7",
            "0.1.6",
            "0.1.5",
            "0.1.3",
            "0.1.2",
            "0.1.1",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-54284.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.689381260Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54284.json",
        "https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-pwgv-4x5q-6m9f",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-54284",
        "https://github.com/andialbrecht/sqlparse/commit/939b129e24c0ad5d51368b1aa72fffcaca76f06f"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1333",
          "CWE-407"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54284.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-54284",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492521,
  "published_at": "2026-08-17T17:43:48.243+00:00"
}