---
title: "TYPO3 12.4.45—What’s Changed?"
url: "https://b13.com/release-digests/v12/typo3-12445-whats-changed"
date: 2026-04-14
modified: 2026-04-14
lastUpdated: 2026-04-14
---

# TYPO3 12.4.45—What’s Changed?

TYPO3 12.4.45—What’s Changed?
==============================

Released: April 14, 2026
Update type: Bugfix and maintenance release

TYPO3 12.4.45 is a maintenance release focused on internal improvements and dependency updates. This release includes performance optimizations, updates to development tools like PHPStan and Node.js, and documentation fixes. No security vulnerabilities are addressed in this version.

Security Fixes
--------------

No security fixes in this release.

Editing & UX Improvements
-----------------------------

No significant user-facing changes in this release.

Backend & Administration
----------------------------

- **Documentation improvements** — Added mention of reaction type listing in configuration module and corrected various documentation typos.

Technical Changes
-----------------

- **Performance optimization** — Improved speed of PolymorphicDeserializer::parseClassNames() for better deserialization performance.
- **Node.js upgrade** — Updated to Node.js 24 LTS for development environment.
- **PHPStan updates** — Updated PHPStan to version 2.1.47 for improved static analysis capabilities.
- **Security maintenance** — Fixed known vulnerable npm development dependencies.
- **Testing improvements** — Added output configuration options for PHPStan runs in runTests.sh script.

- [Download TYPO3 12](https://get.typo3.org/version/12)
- [Official release announcement](https://news.typo3.com/article/typo3-13428-and-12445-maintenance-releases-published)
- [Full changelog](https://docs.typo3.org/c/typo3/cms-core/main/en-us/Changelog-12/Index.html)