CVE-2026-44843 Details
Description
LangChain is a framework for building agents and LLM-powered applications. Prior to 0.3.85 and 1.3.3, LangChain contains older runtime code paths that deserialize run inputs, run outputs, or other application-controlled payloads using overly broad object allowlists. These paths may call load() with allowed_objects="all". This does not enable arbitrary Python object deserialization, but it does allow any trusted LangChain-serializable object to be revived, which is broader than these runtime paths require. As a result, attacker-supplied LangChain serialized constructor dictionaries may cause trusted runtime paths to instantiate classes with untrusted constructor arguments. This vulnerability is fixed in 0.3.85 and 1.3.3.
A vulnerability exists in LangChain versions prior to 0.3.85 and 1.3.3, where older runtime code paths deserialize application-controlled payloads using overly broad object allowlists. This issue allows any trusted LangChain-serializable object to be revived, potentially leading to the injection of untrusted constructor arguments into trusted runtime paths. The vulnerability arises when applications accept untrusted structured input, such as JSON, without proper validation, and when attacker-controlled data is preserved in LangChain run inputs or outputs. Affected API paths include 'RunnableWithMessageHistory', 'astream_log()', and 'astream_events(version="v1")'.
Users should migrate to LangChain versions 0.3.85 or 1.3.3 and update their applications to use the currently recommended APIs, avoiding the deprecated surfaces that are no longer recommended for new applications.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 27, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/langchain-ai/langchain/security/advisories/GHSA-pjwx-r37v-7724 | [email protected] | MitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-502 | Deserialization of Untrusted Data | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| langchain langchain | < 0.3.85 >= 1.0.0, < 1.3.3 |
CPE
Remediation
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Change History
6 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jul 23, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 29, 2026 | Initial Analysis | [email protected] |
| May 26, 2026 | New CVE Received | [email protected] |