LangChain is a framework for building LLM-powered applications. Prior to 1.3.1, MongoDBChatMessageHistory does not enforce the documented string type for an untrusted structured session identifier at runtime, allowing the identifier to be interpreted as a MongoDB query condition rather than as a literal value when multiple users' histories are stored in a shared MongoDB collection. An attacker able to invoke chat-history operations can read, modify, or delete another user's stored conversation. Applications using authenticated, server-controlled string identifiers are not affected. This issue is fixed in version 1.3.1.
History

Fri, 09 Oct 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Langchain-ai
Langchain-ai langchainjs
Langchain-ai mongodb
Vendors & Products Langchain-ai
Langchain-ai langchainjs
Langchain-ai mongodb

Tue, 06 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 06 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Description LangChain is a framework for building LLM-powered applications. Prior to 1.3.1, MongoDBChatMessageHistory does not enforce the documented string type for an untrusted structured session identifier at runtime, allowing the identifier to be interpreted as a MongoDB query condition rather than as a literal value when multiple users' histories are stored in a shared MongoDB collection. An attacker able to invoke chat-history operations can read, modify, or delete another user's stored conversation. Applications using authenticated, server-controlled string identifiers are not affected. This issue is fixed in version 1.3.1.
Title LangChain: MongoDBChatMessageHistory query injection can allow cross-session access
Weaknesses CWE-943
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-06T18:01:24.262Z

Updated: 2026-10-06T19:45:43.997Z

Reserved: 2026-10-06T15:33:55.333Z

Link: CVE-2026-106119

cve-icon Vulnrichment

Updated: 2026-10-06T19:45:09.290Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-06T19:17:42.800

Modified: 2026-10-06T20:17:17.820

Link: CVE-2026-106119

cve-icon Redhat

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