0f4f3f74c8
## Summary Bumps `pygments` to `>=2.20.0` across all 21 affected packages to address [CVE-2026-4539](https://github.com/advisories/GHSA-XXXX) — ReDoS via inefficient GUID regex in Pygments. - **Severity:** Low - **Fixed in:** 2.20.0 (was 2.19.2) - **Change:** Added `pygments>=2.20.0` to `constraint-dependencies` in `[tool.uv]` for each package, then ran `uv lock --upgrade-package pygments` to regenerate lock files. Closes Dependabot alerts #3435–#3455. ## Release Note Patch deps ### Test Plan - [x] CI Green 🙏 Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
🦜️🔗 LangChain Classic
Looking for the JS/TS version? Check out LangChain.js.
To help you ship LangChain apps to production faster, check out LangSmith. LangSmith is a unified developer platform for building, testing, and monitoring LLM applications.
Quick Install
pip install langchain-classic
🤔 What is this?
Legacy chains, langchain-community re-exports, indexing API, deprecated functionality, and more.
In most cases, you should be using the main langchain package.
📖 Documentation
For full documentation, see the API reference. For conceptual guides, tutorials, and examples on using LangChain, see the LangChain Docs.
📕 Releases & Versioning
See our Releases and Versioning policies.
💁 Contributing
As an open-source project in a rapidly developing field, we are extremely open to contributions, whether it be in the form of a new feature, improved infrastructure, or better documentation.
For detailed information on how to contribute, see the Contributing Guide.