8.2

CVE-2026-44843: langchain-ai langchain Deserialization of Untrusted Data

CVSS: 8.2v3.1HighAnalyzed
AliasesGHSA-pjwx-r37v-7724PYSEC-2026-2564CGA-2rj5-xgpq-prf5
Published 26-05-2026Last modified 27-05-2026
Open JSON

Vulnerability summary

CVE-2026-44843 is a high (CVSS 8.2) Deserialization of Untrusted Data vulnerability in langchain-ai langchain. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.7% of scored vulnerabilities.

Overall risk
33/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.2/10
010
High · v3.1 (CVE.org)
EPSS score
0.38%
0%100%
Low · -0.02 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CGA-6579-FJ5C-VX4P

Timeline

  1. 26-05-2026
    PublishedVulnerability first disclosed.
  2. 27-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

31%

Versus all other CVEs

30-day change

-0.02 pp

From 0.41% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.38%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard9 products
  • py3-langchain< 1.3.4-r0
  • py3.10-langchain< 1.3.4-r0
  • py3.10-langchain-core< 1.4.0-r0
  • py3.11-langchain< 1.3.4-r0
  • py3.11-langchain-core< 1.4.0-r0
Langchain1 product
Langchain-ai1 product
PyPI1 product
  • langchain-core< 0.3.85 | ≥ 1.0.0, < 1.3.3

4 vendors · 12 products

References

6 links