Executive brief
LangChain's MongoDB checkpoint and store libraries use MongoDB to persist application state across conversations. These libraries fail to properly validate user input in filter parameters, allowing authenticated users to inject MongoDB query operators (like $ne or $regex) directly into database queries. An attacker can bypass tenant isolation and read another tenant's confidential checkpoint data without permission.
Technical details
A NoSQL injection vulnerability exists in langgraph-checkpoint-mongodb (MongoDBSaver.list() and MongoDBSaver.alist()) and langgraph-store-mongodb (MongoDBStore.search()) libraries. The vulnerability arises because the filter parameter passed to these methods is incorporated directly into MongoDB query objects without sanitizing or rejecting MongoDB operator keys (prefixed with $). An authenticated caller who controls the filter input can embed query operators to modify the database query logic. This allows reading checkpoint or store data beyond the intended scope, particularly in multi-tenant deployments where filters enforce tenant isolation. The attack requires authentication and network access to the API, but no user interaction. Patches are available: upgrade langgraph-checkpoint-mongodb to ≥0.3.0 and langgraph-store-mongodb to ≥0.4.0. As a mitigation, strip or escape "
quot; characters from user-supplied filter inputs before passing them to vulnerable methods.Affected products
- LangChain langgraph-checkpoint-mongodb < 0.3.0
- LangChain langgraph-store-mongodb < 0.4.0
Timeline
- 2026-06-05: disclosed: Initial advisory published
- 2026-06-11: patched: Patches released: langgraph-checkpoint-mongodb 0.3.0 and langgraph-store-mongodb 0.4.0
- 2026-08-20: advisory: GitHub Advisory GHSA-533j-2v4q-mw5h published; CVE-2026-55253 assigned
References
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