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pypi / msgpack

msgpack

What changed in msgpack 1, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-18.

2 breaking4 security1 behavior and defaults1 tooling4 fixes and other

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@unstale/cli 0.1.1 on npm

msgpack 112 changes

Breaking changes 2

  • Negative array and map header sizes are now rejected.

    1.2.3release notes

  • Raises OverflowError when use_single_float cannot represent a value.

    1.2.2release notes

Security 4

  • The C extension validates the nanoseconds range when unpacking timestamps.

    1.2.2release notes

  • Fixes a use-after-free in the ExtraData path when input is non-contiguous.

    1.2.2release notes

  • Adds a reentrant guard to feed(), preventing unsafe reentrant calls.

    1.2.2release notes

  • MessagePack for Python: Out-of-bounds read / crash on Unpacker reuse after a caught error

    1.2.1security advisory

Behavior and default changes 1

Tooling 1

  • Wheels are now also built for Pyodide using Emscripten.

    1.2.3release notes

Fixes and other changes 4

  • Fixes memory leaks when map key validation or container hooks fail.

    1.2.3release notes

  • Fixes timestamp precision for far-future datetimes.

    1.2.2release notes

  • The fallback Unpacker.skip() translates RecursionError to StackError.

    1.2.2release notes

  • Improves error handling and reporting when unpacking.

    1.2.2release notes