CVE-2026-106119

LangChain: MongoDBChatMessageHistory query injection can allow cross-session access

Published Oct 6, 2026 CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-m6rx-h84q-8r95 LangChain: MongoDBChatMessageHistory query injection can allow cross-session access
History
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
Type Values Removed Values Added
Metrics ssvc

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

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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 6, 2026, 7:45 PM
Reserved
Oct 6, 2026, 3:33 PM
Status
Awaiting Analysis
Published
Oct 6, 2026, 7:17 PM
Modified
Oct 6, 2026, 8:17 PM