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Luu, T.J.

GHSA-533j-2v4q-mw5h: LangChain MongoDB has NoSQL Operator Injection in MongoDBSaver.list() leading to cross-tenant data exposure

highvulnerability

security

Source: GitHub Advisory DatabaseAugust 20, 2026CVE-2026-55253

Summary

A NoSQL injection vulnerability (a type of attack where an attacker can manipulate database queries by injecting special operators) exists in two MongoDB libraries for LangChain: langgraph-checkpoint-mongodb and langgraph-store-mongodb. The vulnerable methods (MongoDBSaver.list(), MongoDBSaver.alist(), and MongoDBStore.search()) don't properly block MongoDB query operators (special commands prefixed with $) from user input, allowing an authenticated attacker to read data belonging to other users or tenants in a multi-tenant system.

Solution / Mitigation

Upgrade to langgraph-checkpoint-mongodb version 0.3.0 or later, and langgraph-store-mongodb version 0.4.0 or later. If you cannot upgrade immediately, remove or escape MongoDB Query metacharacters such as "$" in your application code before passing any user-controlled input to the filter parameter.