LangChain MongoDB: NoSQL Operator Injection in MongoDBSaver.list() leading to cross-tenant data exposure

{
  "id": "b9dd062c669866d7bbcd5b300971a08da25d9dc479284465f573211401d1a83d",
  "url": "https://osv.dev/vulnerability/CVE-2026-55253",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "LangChain MongoDB: NoSQL Operator Injection in MongoDBSaver.list() leading to cross-tenant data exposure",
    "summary": "LangChain MongoDB provides integrations between MongoDB, Atlas, LangChain, and LangGraph. Prior to langgraph-checkpoint-mongodb 0.3.0 and langgraph-store-mongodb 0.4.0, MongoDBSaver.list(), MongoDBSaver.alist(), and MongoDBStore.search() incorporate filter dictionaries into MongoDB queries without recursively rejecting keys prefixed with $. An authenticated caller who controls a filter argument through HTTP query parameters, request body fields, or agent tool arguments can inject MongoDB Query Language operators such as $regex or $where. In a multi-tenant deployment that uses the filter to enforce per-user or per-tenant isolation, injected operators can bypass intended equality filtering and expose other tenants' checkpoint or store data. Filters constructed entirely from trusted server-side values have lower practical risk. This issue is fixed in langgraph-checkpoint-mongodb 0.3.0 and langgraph-store-mongodb 0.4.0.",
    "evidence": "osv:CVE-2026-55253",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-55253",
      "aliases": [
        "CVE-2026-55253",
        "GHSA-533j-2v4q-mw5h",
        "PYSEC-2026-3859",
        "PYSEC-2026-3860"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/langchain-ai/langchain-mongodb",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1816901a7ec3d760f72c11fda6804205a662faae"
                },
                {
                  "fixed": "6047a6ee188d65ff3e576fc5a343a6896c4dea5c"
                },
                {
                  "fixed": "14a6cc39e67d23fd409cd13a9caae2c329df0a09"
                },
                {
                  "fixed": "240e7ecee432ea006d9fef6ea506bfd2e009a3f4"
                },
                {
                  "fixed": "5465e4d3ea0ef5c88a666a6442bd853ff4bd70e5"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.4.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.3.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "14a6cc39e67d23fd409cd13a9caae2c329df0a09"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "240e7ecee432ea006d9fef6ea506bfd2e009a3f4"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "5465e4d3ea0ef5c88a666a6442bd853ff4bd70e5"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "libs/langgraph-checkpoint-mongodb/v0.1.0a3",
            "libs/mongodb/v0.3.0a0",
            "libs/langgraph-checkpoint-mongodb/v0.1.0a1",
            "langgraph-0.1.0a0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55253.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.677397513Z",
      "provider": "osv",
      "references": [
        "https://github.com/langchain-ai/langchain-mongodb/releases/tag/libs/langgraph-checkpoint-mongodb/v0.4.0",
        "https://github.com/langchain-ai/langchain-mongodb/releases/tag/libs/langgraph-store-mongodb/v0.3.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55253.json",
        "https://github.com/langchain-ai/langchain-mongodb/security/advisories/GHSA-533j-2v4q-mw5h",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55253",
        "https://github.com/langchain-ai/langchain-mongodb/commit/14a6cc39e67d23fd409cd13a9caae2c329df0a09",
        "https://github.com/langchain-ai/langchain-mongodb/commit/240e7ecee432ea006d9fef6ea506bfd2e009a3f4",
        "https://github.com/langchain-ai/langchain-mongodb/commit/5465e4d3ea0ef5c88a666a6442bd853ff4bd70e5",
        "https://github.com/langchain-ai/langchain-mongodb/pull/384"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-943"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55253.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55253",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 505258,
  "published_at": "2026-09-14T17:09:04.088+00:00"
}