Vue 3.5.43

What Changed in Vue 3.5.43

Vue 3.5.43, released September 17, 2026, is a maintenance build that focuses on compiler, hydration, and Suspense reliability. It delivers no new API surface, so most projects can take it in stride with a routine dependency bump.

Compiler and SFC Fixes

The compiler-sfc layer gets the most attention this round. Comment delimiters inside strings and url() blocks are now handled correctly when parsing CSS variables, and the parser restores the await scope when leaving nested blocks. A semicolon is now prepended for await inside switch cases, and parsed parent configs are reused across tsconfig walks, cutting redundant parsing work.

Hydration and Suspense Improvements

Hydration handling becomes more robust: leave hooks now run for hydration placeholders, and the hydration of an interrupting async component unmount no longer leaves dangling DOM. Suspense gains several correctness fixes, including not dropping nested suspense patches during hydration, keeping the boundary pending while its branch is patched, and unmounting DOM that an interrupted async component had claimed.

Reactivity, Runtime, and Types

Reactivity preserves readonly wrappers in array copy methods, and shared utilities tolerate circular references in looseEqual. v-once children are correctly unmounted after a parent rerenders. On the type front, optional props are kept when a runtime prop uses a generic PropType. Together these fixes close edge cases that surface in async-heavy and SSR-backed applications.

What This Means for You

Because 3.5.43 is a pure bug-fix release, the upgrade is low risk. If you rely on Suspense, hydration, or complex SFC CSS variable handling, this is a worthwhile update. Standard npm update commands will pull it in without configuration changes.