RELEASES.md
Released 2026-07-20.
wasmtime-cli to crates.io.
#13902Released 2026-07-20.
Wasmtime now has the WebAssembly GC proposal enabled by default. #13594
Wasmtime now has the WebAssembly exception-handling proposal enabled by default. #13603
Cranelift now supports the compact unwind format on Mach-O platforms. #13586
Wasmtime now supports bounds-checked unsafe intrinsics which take spectre mitigations into account. #13597
The wasmtime::Engine type now supports reflection to determine the value of
most Config options that were selected during creation.
#13671
Support for fibers on unsupported architectures is now supported through an opt-in compile time Cargo feature defining a C API embedders can implement. #13620
Embedders can now create an ArrayRef with a memcpy-style constructor.
#13716
A new Accessor::poll_ready_for_concurrent_call API can be used to detect
when backpressure indicates that a function is ready to be invoked.
#13683
Support for wasi-threads and Wasmtime's wasi-common crate have been removed.
For more information see the associated RFC in Wasmtime.
#13558
The call_indirect instruction of final super types has been optimized when
the GC proposal is enabled.
#13572
Cranelift's *_imm builder helpers have been deprecated in favor of
*_imm_{s,u} helpers.
#13583
The wasmtime CLI's syntax supported for --invoke with components now
supports fully qualified WIT interface names.
#13564
Cranelift's stack_{load,store} instructions have been removed.
#13580
Cranelift's {band,bor,bxor}_not instructions have been removed.
#13590
Cranelift's global_value instruction has been removed.
#13682
The wasmtime wizer subcommand now supports specifying the initialization
function with WAVE for components.
#13582
Wasmtime's codegen on aarch64 for the i32x4.relaxed_dot_i8x16_i7x16_add_s
wasm instruction now uses a single sdot instruction where possible.
#13640
Wasmtime's .wasmtime{traps,addrmap} sections in *.cwasm files are now
significantly smaller.
#13628
Wasmtime now supports removing symbols from *.cwasm files and additionally
has a documentation page about producing minimally-sized *.cwasm outputs.
#13630
Wasmtime now suports resources in the named_imports option of bindgen!.
#13666
Wasmtime now invokes the host's socket_addr_check callback for implicit
binds performed in WASIp3.
#13677
Wasmtime's component-to-component sync-to-sync fused adapters have been optimized. #13695
Cranelift now supports RISC-V's Zvbb extension. #13738
The IPV6_V6ONLY option is now set for UDP sockets.
#13596
Uncaught wasm exceptions at component boundaries are now turned into traps to prevent components catching exceptions from other components. #13613
Addresses being sent do with WASIp3 and UDP are now validated as they are in WASIp2. #13631
GC roots on component model fiber stacks are now properly traced. #13693
An unaligned load when reading debug state slot values has been fixed. #13791
Release notes for previous releases of Wasmtime can be found on the respective release branches of the Wasmtime repository.
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