# Vitest v4.1.12 — Release & Upgrade Intelligence
- **Product:** Vitest (https://vitest.dev)
- **Version:** v4.1.12
- **Released:** Oct 15, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/vitest/updates/v4.1.12/

## Executive Summary (TL;DR)
Vitest v4.1.12. Source highlight:    🐞 Bug Fixes

## Bug Fixes
- **mocker**: Harden manual and redirect mocks [backport to v4] &nbsp;-&nbsp; by @sheremet-va in https://github.com/vitest-dev/vitest/issues/11580 <samp>(b8253)</samp>