GraphQL-core: Denial of service via comment tokens bypassing the parser's max_tokens limit

{
  "id": "0a7e1f90347fb9acbfa4f902ac97c3dee13d2871c26c0553af15e0685c27ccdb",
  "url": "https://osv.dev/vulnerability/CVE-2026-75508",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "GraphQL-core: Denial of service via comment tokens bypassing the parser's max_tokens limit",
    "summary": "GraphQL-core is a Python port of the GraphQL.js reference implementation. From 3.2.3 until 3.2.12 and 3.3.0rc1, the parser's max_tokens limit in Parser.advance_lexer counts only non-comment tokens returned after Lexer.lookahead skips comments. Each skipped comment is still allocated as a Token and retained through token.next and token.prev, allowing a highly compressible comment-padded GraphQL document to pass a low token limit while consuming memory. An unauthenticated remote attacker can exhaust worker memory before AST-based depth or complexity controls run. This issue is fixed in versions 3.2.12 and 3.3.0rc1.",
    "evidence": "osv:CVE-2026-75508",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-75508",
      "aliases": [
        "CVE-2026-75508",
        "GHSA-r77w-qph3-7vf8"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/graphql-python/graphql-core",
              "type": "GIT",
              "events": [
                {
                  "introduced": "430ee891a52d239adadf133d873fdca2a3fe009b"
                },
                {
                  "fixed": "af6addb1bf39e3b111ae7b805d774326a02f1079"
                },
                {
                  "introduced": "f7e937ca298d90bca74cc1c90904f585c516a0bb"
                },
                {
                  "fixed": "2d72d39ce7107226b9bcd5cc47835a19da0c2c87"
                },
                {
                  "fixed": "437dea102e92fdf05a2971ca76787c5a5bad875a"
                },
                {
                  "fixed": "80ef435a1808fbbcc4aaac63ae76771a1c91002d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "3.2.3"
                      },
                      {
                        "fixed": "3.2.12"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "3.3.0a3"
                      },
                      {
                        "fixed": "3.3.0rc1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "437dea102e92fdf05a2971ca76787c5a5bad875a"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "80ef435a1808fbbcc4aaac63ae76771a1c91002d"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "af6addb1bf39e3b111ae7b805d774326a02f1079"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.2.12"
                  },
                  {
                    "range": [
                      {
                        "fixed": "2d72d39ce7107226b9bcd5cc47835a19da0c2c87"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.3.0rc1"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v3.2.11",
            "v3.3.0rc0",
            "v3.3.0b2",
            "v3.3.0b1",
            "v3.3.0b0",
            "v3.3.0a14",
            "v3.3.0a13",
            "v3.2.10",
            "v3.2.9",
            "v3.2.8",
            "v3.3.0a12",
            "v3.2.7",
            "v3.3.0a11",
            "v3.3.0a10",
            "v3.3.0a9",
            "v3.3.0a8",
            "v3.2.6",
            "v3.3.0a7",
            "v3.2.5",
            "v3.2.4",
            "v3.2.3",
            "v3.3.0a6",
            "v3.3.0a5",
            "v3.3.0a4",
            "v3.3.0a3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-75508.json"
          }
        }
      ],
      "modified": "2026-10-31T02:30:27.277957063Z",
      "provider": "osv",
      "references": [
        "https://github.com/graphql-python/graphql-core/releases/tag/v3.2.12",
        "https://github.com/graphql-python/graphql-core/releases/tag/v3.3.0rc1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75508.json",
        "https://github.com/graphql-python/graphql-core/security/advisories/GHSA-r77w-qph3-7vf8",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-75508",
        "https://github.com/graphql-python/graphql-core/commit/437dea102e92fdf05a2971ca76787c5a5bad875a",
        "https://github.com/graphql-python/graphql-core/commit/80ef435a1808fbbcc4aaac63ae76771a1c91002d"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-400",
          "CWE-770"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75508.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-75508",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 498157,
  "published_at": "2026-10-22T16:10:17.124+00:00"
}