Vulnerability · Published Sep 14, 2026 · Assigned by GitHub_M
CVE-2026-55253LangChain MongoDB: NoSQL Operator Injection in MongoDBSaver.list() leading to cross-tenant data exposure
High 7.7
In plain English
A high-severity security flaw in langchain-mongodb from langchain-ai. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | langgraph-checkpoint-mongodb | 0.3.0 | GHSA-533j-2v4q-mw5h |
| PyPI | langgraph-checkpoint-mongodb | 0.3.0 | PYSEC-2026-3859 |
| PyPI | langgraph-store-mongodb | 0.4.0 | GHSA-533j-2v4q-mw5h |
| PyPI | langgraph-store-mongodb | 0.4.0 | PYSEC-2026-3860 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| langchain-ai | langchain-mongodb | < 0.4.0 |
| langchain-ai | langgraph-checkpoint-mongodb | < 0.3.0 |
| langchain-ai | langgraph-store-mongodb | < 0.4.0 |
Weakness: CWE-943 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
References
- https://github.com/langchain-ai/langchain-mongodb/security/advisories/GHSA-533j-2v4q-mw5h x_refsource_CONFIRM
- https://github.com/langchain-ai/langchain-mongodb/pull/384 x_refsource_MISC
- https://github.com/langchain-ai/langchain-mongodb/commit/14a6cc39e67d23fd409cd13a9caae2c329df0a09 x_refsource_MISC
- https://github.com/langchain-ai/langchain-mongodb/commit/240e7ecee432ea006d9fef6ea506bfd2e009a3f4 x_refsource_MISC
- https://github.com/langchain-ai/langchain-mongodb/commit/5465e4d3ea0ef5c88a666a6442bd853ff4bd70e5 x_refsource_MISC
- https://github.com/langchain-ai/langchain-mongodb/releases/tag/libs/langgraph-checkpoint-mongodb/v0.4.0 x_refsource_MISC
- https://github.com/langchain-ai/langchain-mongodb/releases/tag/libs/langgraph-store-mongodb/v0.3.0 x_refsource_MISC