sqlparse: Reindentation of tuple lists causes near-cap quadratic CPU consumption

{
  "id": "4a2be3f40154d28c92280ebf5dc9085839304b281b4d7ff78516fcd71e78291e",
  "url": "https://osv.dev/vulnerability/CVE-2026-84305",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "sqlparse: Reindentation of tuple lists causes near-cap quadratic CPU consumption",
    "summary": "sqlparse is a non-validating SQL parser module for Python. Prior to 0.6.0, sqlparse.format(sql, reindent=True) and sqlformat --reindent route attacker-controlled parenthesized tuple lists through ReindentFilter._get_offset() in sqlparse/filters/reindent.py, where _flatten_up_to_token() repeatedly rebuilds and joins the statement prefix. Thousands of offset calculations walk an expanding token tree, producing quadratic CPU consumption for inputs that remain below MAX_GROUPING_TOKENS and causing request delays, reduced throughput, or worker starvation. This issue is fixed in version 0.6.0.",
    "evidence": "osv:CVE-2026-84305",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-84305",
      "aliases": [
        "CVE-2026-84305",
        "GHSA-cfqr-cjx5-5jcm",
        "PYSEC-2026-3923"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/andialbrecht/sqlparse",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2f40da99b50d81135aecf96f6b08fcfa338a96de"
                },
                {
                  "fixed": "a51df6d9e2d31b44be9adb6bc8732517db6bf96b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.6.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "a51df6d9e2d31b44be9adb6bc8732517db6bf96b"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "2f40da99b50d81135aecf96f6b08fcfa338a96de"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "0.6.0"
                  }
                ]
              }
            }
          ],
          "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-2026-84305.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.672542761Z",
      "provider": "osv",
      "references": [
        "https://github.com/andialbrecht/sqlparse/releases/tag/0.6.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84305.json",
        "https://github.com/andialbrecht/sqlparse/security/advisories/GHSA-cfqr-cjx5-5jcm",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-84305",
        "https://github.com/andialbrecht/sqlparse/commit/a51df6d9e2d31b44be9adb6bc8732517db6bf96b"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-407"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84305.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-84305",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 489168,
  "published_at": "2026-09-01T18:33:10.969+00:00"
}