# CVE-2025-65106: PYSEC-2026-1518 - LangChain Vulnerable to Template Injection via Attribute Access in Prompt Templates

Source: https://junglewise.ai/threats/cve-2025-65106-langchain-vulnerable-to-template-injection-via-attribute-access  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-11-21  
License: CC BY 4.0 with a link back

CVE-2025-65106 · Severity: medium · CVSS 4 · Published 2025-11-21

LangChain is a framework for building agents and LLM-powered applications. From versions 0.3.79 and prior and 1.0.0 to 1.0.6, a template injection vulnerability exists in LangChain's prompt template system that allows attackers to access Python object internals through template syntax. This vulnerability affects applications that accept untrusted template strings (not just template variables) in ChatPromptTemplate and related prompt template classes. This issue has been patched in versions 0.3.80 and 1.0.7.

Technologies: [langchain-core (PyPI)](https://junglewise.ai/threats/technologies/langchain-core). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2025-65106 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-65106 being exploited in the wild.

**How severe is CVE-2025-65106?** Medium severity, with a CVSS score of 4, published 21 November 2025.

**Which products and versions are affected?** langchain-core (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.80,introduced=1.0.0,fixed=1.0.7, ECOSYSTEM:introduced=1.0.0,fixed=1.0.7.

**Is there a fix for CVE-2025-65106?** Yes. langchain-core (PyPI): upgrade to 1.0.7 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-65106?** 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 1.0.7 or later

  ```sh
  pip install "langchain-core>=1.0.7"
  ```


## Affected products

- langchain-core (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.80,introduced=1.0.0,fixed=1.0.7, ECOSYSTEM:introduced=1.0.0,fixed=1.0.7

## Identifiers

- CVE-2025-65106
- GHSA-6qv9-48xg-fc7f
- PYSEC-2026-1518

## Related threats

- [PYSEC-2026-2562 - LangChain affected by SSRF via image_url token counting in ChatOpenAI.get_num_tokens_from_messages](https://junglewise.ai/threats/cve-2026-26013-langchain-chatopenai-server-side-request-forgery-via-image-token)
- [PYSEC-2026-1517 - langchain-core allows unauthorized users to read arbitrary files from the host file system](https://junglewise.ai/threats/cve-2024-10940-langchain-core-allows-unauthorized-users-to-read-arbitrary-files)
- [PYSEC-2026-1519 - LangChain's XMLOutputParser vulnerable to XML Entity Expansion](https://junglewise.ai/threats/cve-2024-1455-langchain-s-xmloutputparser-vulnerable-to-xml-entity-expansion)
- [LangChain unsafe deserialization in load() via broad object allowlists](https://junglewise.ai/threats/cve-2026-44843-langchain-unsafe-deserialization-in-load-via-broad-object)
- [LangChain incomplete f-string validation in prompt templates](https://junglewise.ai/threats/cve-2026-40087-langchain-incomplete-f-string-validation-in-prompt-templates)