{"id":"CVE-2026-55253","summary":"LangChain MongoDB: NoSQL Operator Injection in MongoDBSaver.list() leading to cross-tenant data exposure","details":"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.","aliases":["GHSA-533j-2v4q-mw5h","PYSEC-2026-3859","PYSEC-2026-3860"],"modified":"2026-10-28T02:30:37.677397513Z","published":"2026-09-14T17:09:04.088Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-943"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55253.json"},"references":[{"type":"WEB","url":"https://github.com/langchain-ai/langchain-mongodb/releases/tag/libs/langgraph-checkpoint-mongodb/v0.4.0"},{"type":"WEB","url":"https://github.com/langchain-ai/langchain-mongodb/releases/tag/libs/langgraph-store-mongodb/v0.3.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55253.json"},{"type":"ADVISORY","url":"https://github.com/langchain-ai/langchain-mongodb/security/advisories/GHSA-533j-2v4q-mw5h"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55253"},{"type":"FIX","url":"https://github.com/langchain-ai/langchain-mongodb/commit/14a6cc39e67d23fd409cd13a9caae2c329df0a09"},{"type":"FIX","url":"https://github.com/langchain-ai/langchain-mongodb/commit/240e7ecee432ea006d9fef6ea506bfd2e009a3f4"},{"type":"FIX","url":"https://github.com/langchain-ai/langchain-mongodb/commit/5465e4d3ea0ef5c88a666a6442bd853ff4bd70e5"},{"type":"FIX","url":"https://github.com/langchain-ai/langchain-mongodb/pull/384"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/langchain-ai/langchain-mongodb","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"},{"source":"AFFECTED_FIELD","strategy":"StringRangeExpression","range":[{"introduced":"0"},{"fixed":"0.3.0"}]},{"range":[{"fixed":"14a6cc39e67d23fd409cd13a9caae2c329df0a09"}],"source":"REFERENCES_COMMIT"},{"source":"REFERENCES_COMMIT","range":[{"fixed":"240e7ecee432ea006d9fef6ea506bfd2e009a3f4"}]},{"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"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"}]}