CVE-2025-6985: HTMLSectionSplitter in langchain-text-splitters XXE via unsafe XSLT parsing

Summary

CVE-2025-6985 affects the HTMLSectionSplitter class in langchain-text-splitters version 0.3.8. The class accepts arbitrary XSLT stylesheets and parses them with lxml.etree.parse() and lxml.etree.XSLT() without hardening, enabling XML External Entity (XXE) attacks. Remote attackers with no authentication, privileges or user interaction could read any file the LangChain process can reach, such as SSH keys, environment files, source code or cloud metadata, in default deployments that enable custom XSLT.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Affected packages in the Exposure Registry

Matched by package name and ecosystem. Each entry shows whether the package delegates to a language model and how many tracked packages depend on it.

• langchain-text-splittersPyPILLM dependency since 2024-03-01 · 6 tracked dependents

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