# CVE-2026-106119: LangChain: MongoDBChatMessageHistory query injection can allow cross-session access

> CVE-2026-106119: LangChain: MongoDBChatMessageHistory query injection can allow cross-session access. CVSS 6.0 (CVSS 4.0).

Canonical: https://rewindex.com/cve/CVE-2026-106119
Last updated: 2026-10-06T20:17:17Z

- Published: 2026-10-06 18:01 UTC · Updated: 2026-10-06 20:17 UTC · Assigner: GitHub\_M
- CVSS: 6.0 (CVSS 4.0) · Severity: Medium
- EPSS: 0.46%, 40th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-943

## 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.

## Affected vendors and products

- @langchain: mongodb
- langchain-ai: langchainjs

## Tracked companies

- [LangChain (LangSmith)](https://rewindex.com/company/langchain-langsmith.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-106119)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-106119)
- [https://github.com/langchain-ai/langchainjs/commit/946e3d856ff1f8ce7f7b9374c83f680a6ada79af](https://github.com/langchain-ai/langchainjs/commit/946e3d856ff1f8ce7f7b9374c83f680a6ada79af)
- [https://github.com/langchain-ai/langchainjs/pull/11672](https://github.com/langchain-ai/langchainjs/pull/11672)
- [https://github.com/langchain-ai/langchainjs/releases/tag/@langchain/mongodb@1.3.1](https://github.com/langchain-ai/langchainjs/releases/tag/@langchain/mongodb@1.3.1)
- [https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-m6rx-h84q-8r95](https://github.com/langchain-ai/langchainjs/security/advisories/GHSA-m6rx-h84q-8r95)

---

_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


---
Canonical: https://rewindex.com/cve/CVE-2026-106119 · Markdown: https://rewindex.com/cve/CVE-2026-106119.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-106119 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:13:31.896Z