Is CVE-2026-44843 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-44843 being exploited in the wild.

How severe is CVE-2026-44843?

High severity, with a CVSS score of 8.2, published 26 May 2026.

Which products and versions are affected?

langchain-core (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.85,introduced=1.0.0,fixed=1.3.3, ECOSYSTEM:introduced=1.0.0,fixed=1.3.3.

Is there a fix for CVE-2026-44843?

Yes. langchain-core (PyPI): upgrade to 1.3.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-44843 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-44843?

Check whether you run langchain-core (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-44843: LangChain unsafe deserialization in load() via broad object allowlists

CVE-2026-44843 · Severity: high · CVSS 8.2 · Published 2026-05-26

LangChain, a popular framework for building AI applications, contains a vulnerability in how it handles certain data formats. An attacker could send specially crafted data to an application using LangChain to trick it into creating unintended objects. This could lead to chat history tampering, unauthorized access to credentials, or the ability to manipulate the AI's behavior.

Technologies: langchain-core (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2026-44843 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-44843 being exploited in the wild.
How severe is CVE-2026-44843?: High severity, with a CVSS score of 8.2, published 26 May 2026.
Which products and versions are affected?: langchain-core (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.85,introduced=1.0.0,fixed=1.3.3, ECOSYSTEM:introduced=1.0.0,fixed=1.3.3.
Is there a fix for CVE-2026-44843?: Yes. langchain-core (PyPI): upgrade to 1.3.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-44843 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-44843?: Check whether you run langchain-core (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

langchain-core (PyPI): upgrade to 1.3.3 or later
```
pip install "langchain-core>=1.3.3"
```

Technical details

LangChain contains a deserialization vulnerability (CWE-502) in older runtime code paths that use overly broad object allowlists (allowed_objects='all'). While it does not allow arbitrary Python object deserialization, it permits the revival of any trusted LangChain-serializable object with attacker-supplied constructor arguments. This can be exploited if an application accepts untrusted JSON input and passes it to affected APIs like RunnableWithMessageHistory, astream_log(), or astream_events(). Attackers can instantiate unexpected classes to achieve prompt injection, credential disclosure, or server-side requests. A related secret-marker validation bypass in _is_lc_secret was also identified and fixed. Patches are available in versions 1.3.3 and 0.3.85.

Affected products

LangChain langchain-core >= 1.0.0, <= 1.3.2; <= 0.3.84

Identifiers

CVE-2026-44843
GHSA-pjwx-r37v-7724
PYSEC-2026-2564

Timeline

2026-05-05: disclosed
2026-05-08: advisory: GitHub Advisory published
2026-05-26: other: NVD published

References

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